chore: add issue reprioritization action (#19758)

Add an issue graduation action with the following configuration:

- run once a week on Sunday
- finds `p2` issues and graduates them to `p1` if there are 20+ reactions
- on every graduated issue, provides an automated message: "This issue has received a significant amount of attention so we are automatically upgrading its priority. A member of the community will see the re-prioritization and provide an update on the issue."

See the action [here](https://github.com/kaizen3031593/issue-graduation-manager).

----

### All Submissions:

* [x] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `cdk-integ` to deploy the infrastructure and generate the snapshot (i.e. `cdk-integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: kaizencc

.github/workflows/issue-reprioritization.yml

@@ -0,0 +1,22 @@
+name: issue-reprioritization
+on: 
+  schedule:
+    - cron: "0 0 * * 0"
+
+jobs:
+  issue-reprioritization:
+    permissions:
+      issues: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: kaizen3031593/issue-reprioritization-manager@main
+        id: reprioritization-manager
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          original-label: p2
+          new-label: p1
+          reprioritization-threshold: 20
+      - uses: kaizen3031593/pr-triage-manager@main
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          on-pulls: ${{ steps.reprioritization-manager.outputs.linked-pulls }}