fix(linux): Properly use and pass run_id

The previous attempt where we set a environment variable for the
artifacts key resulted in a chicken/egg problem: we needed the environment
variable to be able to restore the cached artifacts, but we needed
the cached artifacts in order to be able to read the variables...

This change now properly uses run_id: in `deb-packaging.yml` we can
directly use `run_id` from the context. In `api-verification.yml` we get
it from the payload context.

Cf https://docs.github.com/en/webhooks/webhook-events-and-payloads#workflow_run

.github/workflows/api-verification.yml

@@ -22,22 +22,21 @@ jobs:
       GIT_BRANCH: ${{ steps.environment_step.outputs.GIT_BRANCH }}
       GIT_BASE_BRANCH: ${{ steps.environment_step.outputs.GIT_BASE_BRANCH }}
       GIT_USER: ${{ steps.environment_step.outputs.GIT_USER }}
-      ARTIFACTS_KEY: ${{ steps.environment_step.outputs.ARTIFACTS_KEY }}
 
     steps:
-    - name: Read environment
-      id: environment_step
-      run: |
-        cat artifacts/env >> $GITHUB_OUTPUT
-
     - name: Restore artifacts
       uses: actions/cache/restore@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: |
           artifacts
-        key: ${ARTIFACTS_KEY}
+        key: artifacts-key-${{ github.event.workflow_run.id }}
         restore-keys: artifacts-key-
 
+    - name: Read environment
+      id: environment_step
+      run: |
+        cat artifacts/env >> $GITHUB_OUTPUT
+
   api_verification:
     name: Verify API for libkeymancore.so
     needs: setup_environment

.github/workflows/deb-packaging.yml

@@ -313,14 +313,13 @@ jobs:
         echo "GIT_BRANCH=${{ github.event.client_payload.branch }}" >> artifacts/env
         echo "GIT_BASE_BRANCH=${{ github.event.client_payload.baseBranch }}" >> artifacts/env
         echo "GIT_USER=${{ github.event.client_payload.user }}" >> artifacts/env
-        echo "ARTIFACTS_KEY=artifacts-key-${GITHUB_RUN_ID}" >> artifacts/env
 
     - name: Cache artifacts
       uses: actions/cache/save@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: |
           artifacts
-        key: ${ARTIFACTS_KEY}
+        key: artifacts-key-${{ github.run_id }}
 
   # We intentionally ignore the results of binary_packages_unreleased
   set_status: