Fix Pydantic third-party test (#697)

Author: Viicos

.github/workflows/third_party.yml

@@ -66,7 +66,7 @@ jobs:
         working-directory: pydantic
         run: |
           uv add --editable ../typing-extensions-latest
-          uv sync --group dev
+          uv sync --all-packages --group testing-extra --all-extras
 
           printf "\n\nINSTALLED DEPENDENCIES ARE:\n\n"
           uv pip list