Bump julia-actions/cache from 1 to 2 (JuliaStats#1876)

Bumps [julia-actions/cache](https://github.com/julia-actions/cache) from 1 to 2.
- [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@v1...v2)

---
updated-dependencies:
- dependency-name: julia-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/CI.yml

@@ -37,7 +37,7 @@ jobs:
           # ARM64 on macos-latest is neither supported by older Julia versions nor setup-julia
           arch: ${{ matrix.os == 'macos-latest' && matrix.version != '1.3' && 'aarch64' || 'x64' }}
           show-versioninfo: true
-      - uses: julia-actions/cache@v1
+      - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - run: |