Unpin patch version

Making it more likely that we get a cache hit.

.github/workflows/main.yml

@@ -82,7 +82,7 @@ jobs:
     - name: Set up Python 3.10
       uses: actions/setup-python@v4
       with:
-        python-version: "3.10.9"
+        python-version: "3.10"
     - name: Restore cache
       uses: actions/cache@v3
       with: