fix(ci): Add a cache prestep

.github/workflows/cache.yml

@@ -0,0 +1,55 @@
+---
+name: "CI"
+on:
+  workflow_call:
+jobs:
+  molecule:
+    name: cache
+    runs-on: macos-12
+    env:
+      PYTHON_VERSION: "3.11"
+
+    steps:
+      - name: Check out the codebase
+        uses: actions/checkout@e2f20e631ae6d7dd3b768f56a5d2af784dd54791 # v3 2.5.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Cache pip
+        uses: actions/cache@9b0c1fce7a93df8e3bb8926b0d6e9d89e92f20a7 # 3.0.11
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('./requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
+      - name: Cache Vagrant boxes
+        uses: actions/cache@9b0c1fce7a93df8e3bb8926b0d6e9d89e92f20a7 # 3.0.11
+        with:
+          path: |
+            ~/.vagrant.d/boxes
+          key: vagrant-boxes-${{ hashFiles('**/molecule.yml') }}
+          restore-keys: |
+            vagrant-boxes
+
+      - name: Download Vagrant boxes for all scenarios
+        # To save some cache space, all scenarios share the same cache key.
+        # On the other hand, this means that the cache contents should be
+        # the same across all scenarios. This step ensures that.
+        run: ./.github/download-boxes.sh
+
+      - name: Set up Python ${{ env.PYTHON_VERSION }}
+        uses: actions/setup-python@75f3110429a8c05be0e1bf360334e4cced2b63fa # 2.3.3
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          cache: 'pip' # caching pip dependencies
+
+      - name: Install dependencies
+        run: |
+          echo "::group::Upgrade pip"
+          python3 -m pip install --upgrade pip
+          echo "::endgroup::"
+
+          echo "::group::Install Python requirements from requirements.txt"
+          python3 -m pip install -r requirements.txt
+          echo "::endgroup::"

.github/workflows/ci.yml

@@ -10,6 +10,8 @@ on:
 jobs:
   lint:
     uses: ./.github/workflows/lint.yml
+  cache:
+    uses: ./.github/workflows/cache.yml
   test:
     uses: ./.github/workflows/test.yml
     needs: [lint]