[NDR-56] Refactor Terraform CI workflow to remove continue-on-error flags for format, validate, and plan steps, ensuring clearer error handling in the process

Author: MatthewMoore-NHS

.github/workflows/terraform-dev-to-main-ci.yml

@@ -62,12 +62,10 @@ jobs:
       id: fmt
       run: terraform fmt -check
       working-directory: ./infrastructure
-      continue-on-error: true
 
     - name: terraform validate
       id: validate
       run: terraform validate -no-color
-      continue-on-error: true
 
     - name: Terraform Plan
       id: plan
@@ -77,7 +75,6 @@ jobs:
         echo "summary=$(grep -E 'Plan: [0-9]+ to add, [0-9]+ to change, [0-9]+ to destroy\.|No changes\. Your infrastructure matches the configuration\.' tfplan.txt | sed 's/.*No changes\. Your infrastructure matches the configuration/Plan: no changes/g' | sed 's/.*Plan: //g' | sed 's/\..*//g')" >> $GITHUB_OUTPUT
       working-directory: ./infrastructure
       shell: bash
-      continue-on-error: true
 
     - name: Truncate Plan Output
       id: plan-truncated
@@ -97,7 +94,7 @@ jobs:
 
     - name: Add PR comment
       uses: actions/github-script@v7
-      if: github.event_name == 'pull_request'
+      if: github.event_name == 'pull_request' && (success() || failure())
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}
         script: |