improve speed of PR builds + remove duplicated comments (#1090)

Co-authored-by: Shane Osbourne <sosbourne@duckduckgo.com>

.github/workflows/build-pr.yml

@@ -9,20 +9,25 @@ permissions: write-all
 jobs:
   build:
     if: github.event.action != 'closed'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3
 
-      - name: Set up Node.js
-        uses: actions/setup-node@v3
+      - name: Use Node.js 20
+        uses: actions/setup-node@v1
+        with:
+          node-version: 20.x
+      - uses: actions/cache@v4
         with:
-          node-version: '20'
-          cache: 'npm'
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
 
       - name: Install dependencies
-        run: npm install
+        run: npm ci --verbose
 
       - name: Run build
         run: npm run build
@@ -42,8 +47,18 @@ jobs:
           echo "BRANCH_NAME=pr-releases/pr-${PR_NUMBER}" >> $GITHUB_ENV
           echo "COMMIT_HASH=$(git rev-parse HEAD)" >> $GITHUB_ENV
 
-      - name: Post comment on PR
+      - name: Find Previous Comment
+        uses: peter-evans/find-comment@v2
+        id: find_comment
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: 'Temporary Branch Update'
+          direction: last
+
+      - name: Create Comment Body
         uses: actions/github-script@v7
+        id: create_body
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
@@ -61,15 +76,19 @@ jobs:
               - **Branch Name**: [${branchName}](${branchUrl})
               - **Commit Hash**: [${commitHash}](${commitUrl})
               - **Install Command**: \`npm i github:duckduckgo/content-scope-scripts#${commitHash}\`
-              
+            
               Please use the above install command to update to the latest version.
-            `;
+                `;
+            core.setOutput('comment_body', commentBody);
+            core.setOutput('pr_number', prNumber);
 
-            await github.rest.issues.createComment({
-                ...context.repo,
-                issue_number: prNumber,
-                body: commentBody
-            });
+      - name: Create, or Update the Comment
+        uses: peter-evans/create-or-update-comment@v2
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-id: ${{ steps.find_comment.outputs.comment-id }}
+          body: ${{ steps.create_body.outputs.comment_body }}
+          edit-mode: replace
 
   clean_up:
     if: github.event.action == 'closed'