ci: benchmark julia-actions cache (#13)

Author: bernalde

.github/workflows/ci.yml

@@ -31,6 +31,7 @@ jobs:
         with:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
+      - uses: julia-actions/cache@v3
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       # - uses: julia-actions/julia-processcoverage@v1