chore(deps): update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/check.yml

@@ -62,7 +62,7 @@ jobs:
             extra-deps: "'virtualenv<20.22.0'"
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           # >= 3.11 to ensure there's a recent one to run nox with
           # (assumption: last one listed ends up as "python3")

.github/workflows/release.yml

@@ -26,7 +26,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ needs.release_please.outputs.sha }}
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.10"
       - name: Create release assets