CI fixes

Author: crusaderky

.github/workflows/test-vendor.yml

@@ -50,4 +50,6 @@ jobs:
           cache: true
 
       - name: Test package
-        run: pixi run tests-vendor
+        run: |
+          cd array-api-extra/
+          pixi run tests-vendor

src/array_api_extra/_lib/_compat.pyi

@@ -1,13 +1,13 @@
 from types import ModuleType
+
 from ._typing import Array, Device
 
 class ArrayModule(ModuleType):
     def device(self, x: Array, /) -> Device: ...
 
 def array_namespace(
-    *xs: Array, 
+    *xs: Array,
     api_version: str | None = None,
-    use_compat: bool | None =None,
+    use_compat: bool | None = None,
 ) -> ArrayModule: ...
-
 def device(x: Array, /) -> Device: ...