only run frontend tests if backend passes w/ burnettk

.github/workflows/frontend_tests.yml

@@ -1,8 +1,10 @@
 name: Frontend Tests
 
 on:
-  - push
-  - pull_request
+  workflow_run:
+    workflows: ["Backend Tests"]
+    # completed does not mean success of Tests workflow. see below checking github.event.workflow_run.conclusion
+    types: [completed]
 
 defaults:
   run:
@@ -13,6 +15,7 @@ defaults:
 jobs:
   tests:
     runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
     steps:
       - name: Development Code
         uses: actions/checkout@v3
@@ -57,6 +60,7 @@ jobs:
 
   cypress-run:
     runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
     steps:
       - name: Checkout
         uses: actions/checkout@v3