Enable dependency caching in workflows.

.github/actions/setup-liberation-js/action.yaml

@@ -7,6 +7,8 @@ runs:
       uses: actions/setup-node@v2
       with:
         node-version: "16"
+        cache: npm
+        cache-dependency-path: client/package-lock.json
 
     - name: npm ci
       shell: powershell

.github/actions/setup-liberation-python/action.yaml

@@ -7,6 +7,7 @@ runs:
       uses: actions/setup-python@v2
       with:
         python-version: "3.10"
+        cache: pip
 
     - name: Install environment
       shell: powershell