build(deps): bump actions/cache from 4.1.2 to 4.2.1

Bumps [actions/cache](https://github.com/actions/cache) from 4.1.2 to 4.2.1.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4.1.2...v4.2.1)

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

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
         id: go
 
       - name: Cache Go modules
-        uses: actions/cache@v4.1.2
+        uses: actions/cache@v4.2.1
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}