Bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/vcpkg_ci_amd64.yml

@@ -209,7 +209,7 @@ jobs:
           echo "timestamp=$(date +"%Y-%m-%d-%H:%M:%S" --utc)" >> ${GITHUB_OUTPUT}
 
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{  github.workspace }}/.ccache
           key: ccache-${{ matrix.image.name }}-${{ matrix.image.tag }}-${{ matrix.target_arch }}-${{ matrix.llvm }}-${{ steps.ccache_prep.outputs.timestamp }}

.github/workflows/vcpkg_ci_mac.yml

@@ -158,7 +158,7 @@ jobs:
           echo "timestamp=$(python -c 'from datetime import datetime; print(datetime.utcnow().strftime("%Y-%m-%d-%H:%M:%S"))')" >> ${GITHUB_OUTPUT}
 
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{  github.workspace }}/.ccache
           key: ccache-${{ matrix.os.runner }}-${{ matrix.os.xcode }}-${{ matrix.llvm }}-${{ matrix.target_arch }}-${{ steps.ccache_prep.outputs.timestamp }}