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
2184830377,PR_kwDOAMm_X85pjN8A,8829,"Revert ""Do not attempt to broadcast when global option ``arithmetic_b…",2448579,closed,0,,,7,2024-03-13T20:27:12Z,2024-03-20T15:30:12Z,2024-03-15T03:59:07Z,MEMBER,,0,pydata/xarray/pulls/8829,"…roadcast=False`` (#8784)""

This reverts commit 11f89ecdd41226cf93da8d1e720d2710849cd23e.

Reverting #8784 

Sadly that PR broke a lot of tests by breaking `create_test_data` with
```
from xarray.tests import create_test_data
create_test_data()
```

```
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
Cell In[3], line 2
      1 from xarray.tests import create_test_data
----> 2 create_test_data()

File [~/repos/xarray/xarray/tests/__init__.py:329](http://localhost:8888/lab/workspaces/auto-P/tree/repos/devel/arraylake/~/repos/xarray/xarray/tests/__init__.py#line=328), in create_test_data(seed, add_attrs, dim_sizes)
    327 obj.coords[""numbers""] = (""dim3"", numbers_values)
    328 obj.encoding = {""foo"": ""bar""}
--> 329 assert all(var.values.flags.writeable for var in obj.variables.values())
    330 return obj

AssertionError:
```


Somehow that code changes whether `IndexVariable.values` returns a writeable numpy array. I spent some time debugging but couldn't figure it out.

cc @etienneschalk ","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/8829/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,pull
2184871888,I_kwDOAMm_X86COn_Q,8830,"failing tests, all envs",2448579,closed,0,,,1,2024-03-13T20:56:34Z,2024-03-15T04:06:04Z,2024-03-15T04:06:04Z,MEMBER,,,,"### What happened?

All tests are failing because of an error in `create_test_data`

```
from xarray.tests import create_test_data
create_test_data()
```

```
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
Cell In[3], line 2
      1 from xarray.tests import create_test_data
----> 2 create_test_data()

File [~/repos/xarray/xarray/tests/__init__.py:329](http://localhost:8888/lab/workspaces/auto-P/tree/repos/devel/arraylake/~/repos/xarray/xarray/tests/__init__.py#line=328), in create_test_data(seed, add_attrs, dim_sizes)
    327 obj.coords[""numbers""] = (""dim3"", numbers_values)
    328 obj.encoding = {""foo"": ""bar""}
--> 329 assert all(var.values.flags.writeable for var in obj.variables.values())
    330 return obj

AssertionError:
```

","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/8830/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue
2184606202,PR_kwDOAMm_X85picsD,8827,Add `dask-expr` to environment-3.12.yml,2448579,closed,0,,,0,2024-03-13T18:07:27Z,2024-03-13T20:20:46Z,2024-03-13T20:20:45Z,MEMBER,,0,pydata/xarray/pulls/8827,xref https://github.com/pydata/xarray/actions/runs/8269168819/job/22623800305?pr=8777,"{""url"": ""https://api.github.com/repos/pydata/xarray/issues/8827/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,pull