Bump actions-ext/python/test-sdist

Bumps [actions-ext/python/test-sdist](https://github.com/actions-ext/python) from 6e1b91a408ea89f49bc8aff8724f83826f7b5446 to a3f3953ef26a519ab7b6a56b94d06fa1b31ab3f3.
- [Commits](actions-ext/python@6e1b91a...a3f3953)

---
updated-dependencies:
- dependency-name: actions-ext/python/test-sdist
  dependency-version: a3f3953ef26a519ab7b6a56b94d06fa1b31ab3f3
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/build.yaml

@@ -84,7 +84,7 @@ jobs:
           module: jupyterlab_templates
 
       - name: Test source distribution
-        uses: actions-ext/python/test-sdist@6e1b91a408ea89f49bc8aff8724f83826f7b5446
+        uses: actions-ext/python/test-sdist@a3f3953ef26a519ab7b6a56b94d06fa1b31ab3f3
         with:
           module: jupyterlab_templates