Bump julia-actions/cache from 2.0.7 to 2.1.0

Bumps [julia-actions/cache](https://github.com/julia-actions/cache) from 2.0.7 to 2.1.0.
- [Release notes](https://github.com/julia-actions/cache/releases)
- [Changelog](https://github.com/julia-actions/cache/blob/main/devdocs/making_a_new_release.md)
- [Commits](julia-actions/cache@2b1bf4d...d10a6fd)

---
updated-dependencies:
- dependency-name: julia-actions/cache
  dependency-version: 2.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/exercise-tests.yml

@@ -32,7 +32,7 @@ jobs:
         with:
           version: ${{ matrix.julia-version }}
 
-      - uses: julia-actions/cache@2b1bf4d8a138668ac719ea7ca149b53ed8d8401e
+      - uses: julia-actions/cache@d10a6fd8f31b12404a54613ebad242900567f2b9
 
       - name: Install test dependencies
         run: julia --color=yes --project -e "using Pkg; Pkg.instantiate()"