Bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/check-docs.yml

@@ -31,7 +31,7 @@ jobs:
 
       - name: Use pip cache
         id: pip-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ env.PIP_CACHE_DIR }}
           key: docs-ubuntu-latest-pip-3.11-${{ hashFiles('pyproject.toml') }}

.github/workflows/docs.yml

@@ -28,7 +28,7 @@ jobs:
 
       - name: Use pip cache
         id: pip-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ env.PIP_CACHE_DIR }}
           key: docs-ubuntu-latest-pip-3.11-${{ hashFiles('pyproject.toml') }}

.github/workflows/tests.yml

@@ -46,7 +46,7 @@ jobs:
 
       - name: Use pip cache
         id: pip-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ env.PIP_CACHE_DIR }}
           key: tests-${{ matrix.os }}-pip-${{ matrix.python }}-${{ hashFiles('pyproject.toml') }}