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/docs.yml

@@ -26,7 +26,7 @@ jobs:
           version: "1.5.1"
       - name: Cache dependencies
         id: cache-deps
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .venv
           key: pydeps-${{ hashFiles('**/poetry.lock') }}

.github/workflows/test.yml

@@ -35,7 +35,7 @@ jobs:
           version: ${{ matrix.poetry-version }}
       - name: Cache dependencies
         id: cache-deps
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .venv
           key: pydeps-${{ hashFiles('**/poetry.lock') }}