id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1732874789,I_kwDOAMm_X85nSZIl,7885,drop_indexes is reversed by assign_coords of unrelated coord,4502,closed,0,,,2,2023-05-30T19:35:48Z,2023-08-29T14:23:31Z,2023-08-29T14:23:31Z,NONE,,,,"### What happened?

I dropped an index on one coord, then later called assign_coords to change another unrelated coord.
I expected the index on the original coord to stay dropped.

### What did you expect to happen?

The index was silently created again.

### Minimal Complete Verifiable Example

```Python
import xarray
import numpy as np
ds = xarray.Dataset(
    {'foo': (('x','y'), np.ones((3,5)))},
    coords={'x': [1,2,3], 'y': [4,5,6,7,8]})
ds = ds.drop_indexes('x')
assert 'x' not in ds.indexes
ds = ds.assign_coords(y=ds.y+1)
assert 'x' not in ds.indexes  # Fails
```


### MVCE confirmation

- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [X] Complete example — the example is self-contained, including all data and the text of any traceback.
- [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

### Relevant log output

_No response_

### Anything else we need to know?

In general it would be nice if xarray made it easier to avoid indexes being automatically created.

E.g. right now, as far as I can tell there's no way to avoid an index being created when you construct a DataArray or Dataset with a coordinate of the same name as a dimension.

Admittedly I have a slightly niche use case -- I'm using xarray with wrapped JAX arrays, which can't be converted into pandas indexes. Indexes being (re-)created in these cases isn't just an inconvenience it actually causes a crash.

### Environment

<details>
INSTALLED VERSIONS
------------------
commit: None
python: 3.10.9 (main, Dec  7 2022, 13:47:07) [GCC 12.2.0]
python-bits: 64
OS: Linux
OS-release: 6.1.20-2rodete1-amd64
machine: x86_64
processor: 
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: ('en_US', 'UTF-8')
libhdf5: 1.10.8
libnetcdf: 4.9.0

xarray: 999
pandas: 1.5.3
numpy: 1.24.2
scipy: 1.10.0
netCDF4: 1.6.2
pydap: None
h5netcdf: 1.1.0
h5py: 3.7.0
Nio: None
zarr: 2.13.6+ds
cftime: 1.6.2
nc_time_axis: None
PseudoNetCDF: None
rasterio: 1.3.4
cfgrib: 0.9.10.3
iris: None
bottleneck: 1.3.5
dask: None
distributed: None
matplotlib: 3.6.3
cartopy: None
seaborn: None
numbagg: None
fsspec: 2022.11.0
cupy: None
pint: None
sparse: None
flox: None
numpy_groupies: None
setuptools: 65.6.3
pip3: None
conda: None
pytest: 7.2.1
mypy: None
IPython: 8.5.0
sphinx: 5.3.0
</details>
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/7885/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue
1188262115,I_kwDOAMm_X85G03Dj,6429,FacetGrid padding goes very bad when cartopy projection specified,4502,closed,0,,,2,2022-03-31T15:26:26Z,2023-04-28T13:06:14Z,2023-04-28T13:06:14Z,NONE,,,,"### What happened?

When doing a faceted plot and specifying a projection (via e.g. `subplot_kws=dict(projection=ccrs.PlateCarree())`), the padding becomes very weird (often unusable) and strangely unstable to changes in `size` and `aspect`. For example this produces very bad results:

```python
data = xarray.DataArray(
    dims=('lat', 'lon', 'row', 'col'),
    data=np.ones((180, 360, 2, 2)),
    coords={'lon': np.arange(360), 'lat': np.arange(-90, 90)}
)
xarray.plot.pcolormesh(
    data,
    row='row',
    col='col',
    size=5,
    aspect=1.5,
    subplot_kws=dict(projection=ccrs.PlateCarree()),
)
```

![image](https://user-images.githubusercontent.com/4502/161090986-6dd7fd6b-5950-40aa-a78e-7699061b3a15.png)

whereas if you change `size` from 5 to 4, you suddenly get a much better (although still not quite right) layout:

![image](https://user-images.githubusercontent.com/4502/161091130-7e6b9580-d39c-4a89-9756-932bafff9ff0.png)



### What did you expect to happen?

I expected a layout closer to what you get if you comment out `subplot_kws=dict(projection=ccrs.PlateCarree()),` above:

![image](https://user-images.githubusercontent.com/4502/161091524-8993534f-efd7-45d3-9b4c-8e25099fb53e.png)


### Minimal Complete Verifiable Example

```Python
import xarray
import cartopy.crs as ccrs
import numpy as np

data = xarray.DataArray(
    dims=('lat', 'lon', 'row', 'col'),
    data=np.ones((180, 360, 2, 2)),
    coords={'lon': np.arange(360), 'lat': np.arange(-90, 90)}
)
xarray.plot.pcolormesh(
    data,
    row='row',
    col='col',
    size=5,
    aspect=1.5,
    subplot_kws=dict(projection=ccrs.PlateCarree()),
)
```


### Relevant log output

In the case where the layout isn't (as) broken, I see a warning: 

`.../xarray/plot/facetgrid.py:394: UserWarning: Tight layout not applied. tight_layout cannot make axes width small enough to accommodate all axes decorations`

It seems that when tight_layout does manage to get applied, things really go wrong.
Perhaps at a minimum we could have a way to disable tight_layout? (which currently seems to be mandatory)

### Anything else we need to know?

_No response_

### Environment

INSTALLED VERSIONS
------------------
commit: None
python: 3.7.10 (stable, redacted, redacted) 
[Clang google3-trunk (e5b1b9edb8b6f6cd926c2ba3e1ad1b6f767021d6)]
python-bits: 64
OS: Linux
OS-release: 4.15.0-smp-920.39.0.0
machine: x86_64
processor: 
byteorder: little
LC_ALL: en_US.UTF-8
LANG: None
LOCALE: ('en_US', 'UTF-8')
libhdf5: 1.12.1
libnetcdf: 4.6.1

xarray: 0.18.2
pandas: 1.1.5
numpy: 1.21.5
scipy: 1.2.1
netCDF4: 1.4.1
pydap: None
h5netcdf: 0.11.0
h5py: 3.2.1
Nio: None
zarr: 2.7.0
cftime: 1.0.0
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: 3.3.4
cartopy: 0+unknown
seaborn: 0.11.1
numbagg: None
pint: None
setuptools: unknown
pip: None
conda: None
pytest: None
IPython: 3.2.3
sphinx: None","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/6429/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue