Bump actions/cache from 4 to 6

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 6.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...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>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -124,7 +124,7 @@ jobs:
         python-version: '3.x'
         cache: pip
         cache-dependency-path: .github/workflows/requirements.txt
-    - uses: actions/cache@v4
+    - uses: actions/cache@v6
       with:
         path: ${{ env.MESON_PACKAGE_CACHE }}
         key: wraps-${{ hashFiles('subprojects/*.wrap') }}

.github/workflows/release.yml

@@ -43,7 +43,7 @@ jobs:
         python-version: '3.x'
         cache: pip
         cache-dependency-path: .github/workflows/requirements.txt
-    - uses: actions/cache@v4
+    - uses: actions/cache@v6
       with:
         path: ${{ env.MESON_PACKAGE_CACHE }}
         key: wraps-${{ hashFiles('subprojects/*.wrap') }}