perf: run tf_plan_apply on PR merges

Author: andhreljaKern

.github/workflows/tf_plan_apply.yml

@@ -87,7 +87,7 @@ jobs:
         
     # Save plan to artifacts  
     - name: Publish OpenTofu Plan
-      if: ${{ github.event_name == 'push' || github.event_name == 'workflow_dispatch' }}
+      if: ${{ github.event_name == 'push' || github.event_name == 'workflow_dispatch' || github.event.pull_request.merged }}
       uses: actions/upload-artifact@v4
       with:
         name: tfplan
@@ -96,7 +96,7 @@ jobs:
   tofu-apply:
     name: 'OpenTofu Apply'
     needs: [tofu-plan]
-    if: ${{ (github.event_name == 'push' || github.event_name == 'workflow_dispatch') && needs.tofu-plan.outputs.tf_plan_exit_code == 2 }}
+    if: ${{ (github.event_name == 'push' || github.event_name == 'workflow_dispatch' || github.event.pull_request.merged) && needs.tofu-plan.outputs.tf_plan_exit_code == 2 }}
     runs-on: ${{ fromJSON(inputs.runs_on) }}
     environment: ${{ github.ref_name }}
     env: