Bump actions/cache from 4.1.2 to 4.2.0

Bumps [actions/cache](https://github.com/actions/cache) from 4.1.2 to 4.2.0.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4.1.2...v4.2.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         uses: actions/checkout@v4.2.2
 
       - name: Cache Swift PM
-        uses: actions/cache@v4.1.2
+        uses: actions/cache@v4.2.0
         with:
           path: .build
           key: ${{ runner.os }}-${{ matrix.swift }}-ci-spm-${{ hashFiles('Package.swift') }}