Skip GitHub Actions verify and regression steps from manual runs

We already skip package tests as we have coverage in our PR tests already

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ on:
         type: boolean
 
 concurrency:
-  group: tests-${{ github.head_ref || github.run_id }}
+  group: tests-${{ inputs.runner || 'ubuntu-latest' }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
 jobs:
@@ -190,6 +190,9 @@ jobs:
     runs-on: ${{ inputs.runner || 'ubuntu-latest' }}
     needs: [install, build]
 
+    # Skip when scheduled or run manually
+    if: ${{ !inputs.runner }}
+
     strategy:
       fail-fast: false
 
@@ -269,6 +272,9 @@ jobs:
     name: Percy
     needs: [install, build]
 
+    # Skip when scheduled or run manually
+    if: ${{ !inputs.runner }}
+
     # Run existing "Percy screenshots" workflow
     # (after install and build have been cached)
     uses: ./.github/workflows/screenshots.yml