DOC, MAINT: workaround for py311 docs

* temporary workaround to allow SciPy docs
to build on `main` with Python `3.11` until
an upstream fix for gh-19228 is available

* I thought about guarding this filter by
Python version, but didn't seem worth it,
but can change that if really desired

* locally, `python dev.py doc -j 32` has a
`0` exit code/succeeds with `3.11`

[skip cirrus] [skip actions]

doc/source/conf.py

@@ -183,6 +183,12 @@
     message=r'There is no current event loop',
     category=DeprecationWarning,
 )
+# TODO: remove after gh-19228 resolved:
+warnings.filterwarnings(
+    'ignore',
+    message=r'.*path is deprecated.*',
+    category=DeprecationWarning,
+)
 
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