Use julia actions cache in CI (#440)

.github/workflows/ci.yml

@@ -17,6 +17,11 @@ concurrency:
   group: build-${{ github.event.pull_request.number || github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
+# needed to allow julia-actions/cache to delete old caches that it has created
+permissions:
+  actions: write
+  contents: read
+
 jobs:
   pre_job:
     # continue-on-error: true # Uncomment once integration is finished
@@ -47,16 +52,7 @@ jobs:
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}
-      - uses: actions/cache@v4
-        env:
-          cache-name: cache-artifacts
-        with:
-          path: ~/.julia/artifacts
-          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-test-${{ env.cache-name }}-
-            ${{ runner.os }}-test-
-            ${{ runner.os }}-
+      - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1