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/validations.yaml

@@ -67,7 +67,7 @@ jobs:
       # why not use actions/upload-artifact? It is very slow (3 minutes to upload ~600MB of data, vs 10 seconds with this approach).
       # see https://github.com/actions/upload-artifact/issues/199 for more info
       - name: Upload snapshot artifacts
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         with:
           path: snapshot
           key: snapshot-build-${{ github.run_id }}
@@ -86,7 +86,7 @@ jobs:
       - uses: actions/checkout@master
 
       - name: Download snapshot build
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: snapshot
           key: snapshot-build-${{ github.run_id }}
@@ -108,7 +108,7 @@ jobs:
       - uses: actions/checkout@master
 
       - name: Download snapshot build
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: snapshot
           key: snapshot-build-${{ github.run_id }}