Bump the github-actions group across 1 directory with 2 updates

Bumps the github-actions group with 2 updates in the / directory: [actions/checkout](https://github.com/actions/checkout) and [actions/upload-artifact](https://github.com/actions/upload-artifact).


Updates `actions/checkout` from 5 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

Updates `actions/upload-artifact` from 4 to 5
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

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

Author: dependabot[bot]

.github/workflows/tests.yml

@@ -107,7 +107,7 @@ jobs:
 
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
@@ -173,7 +173,7 @@ jobs:
           ls -l dist
           twine check dist/*
       - name: Upload RelStorage wheel
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: RelStorage-${{ runner.os }}-${{ matrix.python-version }}.whl
           path: dist/*whl
@@ -257,7 +257,7 @@ jobs:
     name: ${{ matrix.image }}
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with:
@@ -271,7 +271,7 @@ jobs:
           DOCKER_IMAGE: quay.io/pypa/${{ matrix.image }}
         run: bash ./scripts/releases/make-manylinux
       - name: Store RelStorage wheels
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           path: wheelhouse/*whl
           name: ${{ matrix.image }}_wheels.zip