Cache dependencies in GitHub Actions

For:
https://github.com/ClinGen/stanford-hci/issues/8

.github/workflows/check.yml

@@ -17,10 +17,28 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: 20
-      - name: Install front end and back end dependencies
-        run: |
-          npm install
-          pip install -r requirements.txt
+      - name: Cache Python dependencies (or restore previously cached)
+        id: python-cache
+        uses: actions/cache@v4
+        with:
+          path: venv  # It's important to have a single directory that gets cached.
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+      - name: Install Python dependencies
+        if: steps.python-cache.outputs.cache-hit != 'true'
+        run: python -m venv venv && source ./venv/bin/activate && pip install -r requirements.txt
+      - name: Cache NPM dependencies (or restore previously cached)
+        id: npm-cache
+        uses: actions/cache@v4
+        with:
+          path: node_modules  # It's important to have a single directory that gets cached.
+          key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+      - name: Install NPM dependencies
+        if: steps.npm-cache.outputs.cache-hit != 'true'
+        run: npm install
       - name: Format the front end and back end code
         run: invoke fmt
       - name: Lint the front end and back end code