DONOTMERGE: try running CI with this pip, it *should* use built wheels from cache

.github/workflows/ci.yml

@@ -13,7 +13,37 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
   cancel-in-progress: true
 jobs:
+  deps:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v3
+      - name: Install platform dependencies
+        run: |
+          sudo apt -y update
+          sudo apt -y install libcurl4-openssl-dev libssl-dev pkg-config libxml2-dev libxslt-dev
+      - uses: actions/setup-python@v4
+        with:
+          python-version-file: '.python-version'
+      - name: pip cache
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache/pip
+          key: pip-${{ runner.os }}
+      - name: Cache built Python environment
+        uses: actions/cache@v3
+        with:
+          path: ${{ env.pythonLocation }}
+          key: ${{ runner.os }}-${{ env.pythonLocation }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}
+      - name: Install Python dependencies
+        run: |
+          pip install -U setuptools wheel
+          pip install 'pip @ git+https://github.com/pypa/pip@refs/pull/11897/head'
+          pip install -r requirements.txt --no-deps
+          pip install -r requirements/dev.txt
+          pip check
   test:
+    needs: deps
     strategy:
       matrix:
         include:
@@ -54,25 +84,24 @@ jobs:
       - name: Install platform dependencies
         run: |
           sudo apt -y update
-          sudo apt -y install libcurl4-openssl-dev libssl-dev pkg-config
+          sudo apt -y install libxml2 libxslt1.1 libcurl4
       - uses: actions/setup-python@v4
         with:
           python-version-file: '.python-version'
-          cache: 'pip'
-          cache-dependency-path: |
-            requirements.txt
-            requirements/*.txt
-      - name: Cache common Python cache paths
-        uses: actions/cache@v3
+      - name: Restore built Python environment from deps
+        uses: actions/cache/restore@v3
         with:
-          path: |
-            .cache
-            .mypy_cache
-            ${{ env.pythonLocation }}
+          path: ${{ env.pythonLocation }}
           key: ${{ runner.os }}-${{ env.pythonLocation }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}
+      - name: mypy cache
+        uses: actions/cache@v3
+        with:
+          path: .mypy_cache
+          key: mypy-${{ runner.os }}-${{ hashFiles('requirements.txt', 'requirements/*.txt') }}
       - name: Install Python dependencies
         run: |
-          pip install -U pip setuptools wheel
+          pip install -U setuptools wheel
+          pip install 'pip @ git+https://github.com/pypa/pip@refs/pull/11897/head'
           pip install -r requirements.txt --no-deps
           pip install -r requirements/dev.txt
           pip check