chore(deps): 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/ffmpeg-release.yml

@@ -72,15 +72,15 @@ jobs:
         run: brew update && brew install yasm autoconf ragel meson nasm automake libtool python3
 
       - name: Cache FFmpeg source downloads
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .build/downloads
           key: ${{ runner.os }}-${{ runner.arch }}-ffmpeg-downloads-${{ hashFiles('internal/builder/libraries.go') }}
           restore-keys: |
             ${{ runner.os }}-${{ runner.arch }}-ffmpeg-downloads-
 
       - name: Cache compiled dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .build/staging

.github/workflows/ffmpeg-test.yml

@@ -69,7 +69,7 @@ jobs:
           echo "buildsystems-hash=$(sha256sum internal/builder/buildsystems.go | cut -d' ' -f1 | head -c 8)" >> $GITHUB_OUTPUT
 
       - name: Cache FFmpeg source downloads
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .build/downloads
           # Workaround for GitHub Actions bug: https://github.com/actions/runner-images/issues/13341
@@ -79,7 +79,7 @@ jobs:
             ${{ runner.os }}-${{ runner.arch }}-ffmpeg-downloads-
 
       - name: Cache compiled dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .build/staging