add suggestion to use cache action if no depot is detected (#41)

.github/workflows/ci.yml

@@ -58,18 +58,9 @@ jobs:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
 
-      - uses: actions/cache@v3
-        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: ./.github/actions/julia-buildpkg
+        with:
+          ignore-no-cache: true
         env:
           JULIA_PKG_SERVER: ${{ matrix.pkg-server }}