Bump actions/cache from 2 to 4 (#68)

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v2...v4)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/TestJuliaVersions.yml

@@ -26,7 +26,7 @@ jobs:
 
       - name: Cache preCICE
         id: cache-libprecice
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: libprecice3_3.1.0_focal.deb
           key: libprecice3_3.1.0_focal.deb1