coverage: do not update cache if build failed

Author: Meow404

.github/workflows/coverage.yml

@@ -1,5 +1,5 @@
 name: C3 Coverage
-on: 
+on:
   push:
     branches:
       - main
@@ -11,11 +11,11 @@ jobs:
     concurrency:
       group: ci-${{ github.ref }}
       cancel-in-progress: true
-    container: 
+    container:
       image: ghcr.io/dairlab/docker-dair/noble-dair-base:v1.42
       credentials:
-       username: ${{ github.actor }}
-       password: ${{ secrets.GITHUB_TOKEN }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
       options: --cpus 4
     steps:
       - name: Check out repository code
@@ -30,13 +30,14 @@ jobs:
           key: c3-bazel-cov-cache-${{ hashFiles('**/BUILD.bazel') }}
           restore-keys: |
             c3-bazel-cov-cache-
-      - name: Generate Coverage 
+      - name: Generate Coverage
+        id: generate-coverage
         run: bazel coverage
-              --combined_report=lcov
-              --local_resources=ram=24000
-              --local_resources=cpu=4
-              --jobs=4
-              //...
+          --combined_report=lcov
+          --local_resources=ram=24000
+          --local_resources=cpu=4
+          --jobs=4
+          //...
       - name: Report code coverage
         uses: zgosalvez/[email protected]
         with:
@@ -47,7 +48,7 @@ jobs:
           update-comment: true
       - name: Save coverage cache
         id: c3-cov-cache-save
-        if: always() && !cancelled() && steps.c3-cov-cache-restore.outputs.cache-hit != 'true'
+        if: always() && !cancelled() && steps.c3-cov-cache-restore.outputs.cache-hit != 'true' && steps.generate-coverage.outcome == 'success'
         uses: actions/cache/save@v4
         with:
           key: ${{ steps.c3-cov-cache-restore.outputs.cache-primary-key }}