ci: add generic make-or-fetch-artifact action

Author: SimonThormeyer

.github/actions/make-or-fetch-artifact/action.yml

@@ -0,0 +1,44 @@
+name: Fetch or make an artifact
+description: Fetch an artifact with a given key. If it doesn't exist, run the given command and upload it.
+inputs:
+  name:
+    description: The artifact name
+    required: true
+  make-rule:
+    description: The GNU make rule which produces the artifact
+    required: true
+  target-path:
+    description: The relative path of the final artifact(s)
+    required: false
+    default: 'target/release'
+  # TODO(SimonThormeyer) not supported yet; will be added in a subsequent PR.
+  preserve-dirs:
+    description: Whether to use `tar` to compress/extract the final artifact(s).
+      Required to be `true` if the dir hierarchy needs to be preserved.
+      multiple rust targets because keys cannot contain commas.
+    required: false
+    default: 'false'
+runs:
+  using: composite
+  steps:
+    - name: Attempt to download the artifact
+      uses: actions/download-artifact@v5
+      with:
+        name: ${{ inputs.name }}
+        path: "${{ inputs.target-path }}"
+      continue-on-error: true
+      id: artifact-download
+
+    - name: Run make ${{ inputs.make-rule }} if needed
+      if: ${{ steps.artifact-download.outcome == 'failure' }}
+      run: make ${{ inputs.make-rule }}
+      shell: bash
+
+    - name: Upload artifact if needed
+      if: ${{ steps.artifact-download.outcome == 'failure' }} && github.repository == 'wireapp/core-crypto'
+      uses: actions/upload-artifact@v4
+      with:
+        name: ${{ inputs.name }}
+        path: ${{ inputs.target-path }}
+        retention-days: 1
+        overwrite: 'true'