chore(ci): reactivate on_merged_pr workflow

Author: heitorlessa

Diff for: .github/disabled_on_merged_pr.yml

@@ -0,0 +1,30 @@
+module.exports = async ({github, context}) => {
+    const prBody = context.payload.body;
+    const prNumber = context.payload.number;
+    const releaseLabel = process.env.RELEASE_LABEL;
+    const maintainersTeam = process.env.MAINTAINERS_TEAM
+
+    const RELATED_ISSUE_REGEX = /Issue number:.+(\d)/
+
+    const matcher = new RegExp(RELATED_ISSUE_REGEX)
+    const isMatch = matcher.exec(prBody)
+    if (isMatch != null) {
+        let relatedIssueNumber = isMatch[1]
+        console.info(`Auto-labeling related issue ${relatedIssueNumber} for release`)
+
+        return await github.rest.issues.addLabels({
+          issue_number: relatedIssueNumber,
+          owner: context.repo.owner,
+          repo: context.repo.repo,
+          labels: [releaseLabel]
+        })
+    } else {
+      let msg = `${maintainersTeam} No related issues found. Please ensure '${releaseLabel}' label is applied before releasing.`;
+      return await github.rest.issues.createComment({
+        owner: context.repo.owner,
+        repo: context.repo.repo,
+        body: msg,
+        issue_number: prNumber,
+      });
+    }
+}

Diff for: .github/scripts/label_related_issue.js

@@ -0,0 +1,27 @@
+# Maintenance: Verify why we're having permissions issues even with write scope, then re-enable it.
+# logs: https://github.com/awslabs/aws-lambda-powertools-python/runs/7030238348?check_suite_focus=true
+
+on:
+  pull_request:
+    types:
+      - closed
+
+env:
+  RELEASE_LABEL: "pending-release"
+  MAINTAINERS_TEAM: "@awslabs/aws-lambda-powertools-python"
+
+jobs:
+  release_label_on_merge:
+    if: github.event.pull_request.merged == true && github.event.pull_request.user.login != 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write # required for new scoped token
+      pull-requests: write # required for new scoped token
+    steps:
+      - name: "Label PR related issue for release"
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const script = require('.github/scripts/label_related_issue.js')
+            await script({github, context, core})