Attempt to improve caching

.github/actions/setup/action.yml

@@ -16,12 +16,18 @@ inputs:
 runs:
   using: "composite"
   steps:
+    - name: Write file with install flags
+      run: |
+        echo "${{ inputs.pdm-dependency-install-flags }}" > pdm-install-flags.txt
     - name: Setup PDM
       id: setup-pdm
       uses: pdm-project/[email protected]
       with:
         python-version: ${{ inputs.python-version }}
         cache: true
+        cache-dependency-path: |
+          ./pdm.lock
+          ./pdm-install-flags.txt
     - name: Install dependencies
       shell: bash
       if: ${{ (inputs.run-pdm-install == 'true')  && (steps.setup-pdm.outputs.cache-hit != 'true') }}

.gitignore

@@ -1,6 +1,9 @@
 # pdm stuff
 .pdm-python
 
+# CI stuff
+pdm-install-flags.txt
+
 # licence check
 licence-check.txt