Ignore os.getuid() mypy error

Error happens on Windows and can be ignored because we check
`getuid()` using `hasattr` right above.

Author: nicoddemus

src/_pytest/tmpdir.py

@@ -131,8 +131,8 @@ def getbasetemp(self) -> Path:
             # rootdir's permissions. Historically 0o755 was used, so we can't
             # just error out on this, at least for a while.
             if hasattr(os, "getuid"):
+                uid = os.getuid()  # type:ignore[attr-defined]
                 rootdir_stat = rootdir.stat()
-                uid = os.getuid()
                 # getuid shouldn't fail, but cpython defines such a case.
                 # Let's hope for the best.
                 if uid != -1: