Bump actions/cache from 5 to 6

Bumps [actions/cache](https://github.com/actions/cache) from 5 to 6.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ci-windows.yml

@@ -45,7 +45,7 @@ jobs:
 
       - name: Try to restore libraries from the cache
         if: github.event_name != 'release'
-        uses: actions/cache/restore@v5
+        uses: actions/cache/restore@v6
         id: library-cache
         with:
           key: Conan VS${{ env.VisualStudioVersion }} ${{ env.BUILD_TYPE }} ${{ hashFiles(env.CONAN_FILE) }}
@@ -60,7 +60,7 @@ jobs:
 
       - name: Save libraries to the cache
         if: steps.library-cache.outputs.cache-hit != 'true' && github.event_name != 'release'
-        uses: actions/cache/save@v5
+        uses: actions/cache/save@v6
         with:
           key: ${{ steps.library-cache.outputs.cache-primary-key }}
           path: ${{ env.CONAN_HOME }}\p