Internals: Add 'RTLMeter PR results' workflow

Workflows triggered for a PR from a fork can never have write
permissions, so to post a comment on a PR, it must be done from a
separate workflow triggered by 'workflow_run' in the main repository.

.github/workflows/rtlmeter-pr-results.yml

@@ -0,0 +1,35 @@
+---
+# DESCRIPTION: Github actions config
+# This name is key to badges in README.rst, so we use the name build
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+name: RTLMeter PR results
+
+on:
+  workflow_run:
+    workflows:
+      - RTLMeter
+    types:
+      - completed
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success' }}
+    permissions:
+      actions: read
+      pull-requests: write
+    steps:
+      - name: Download report
+        uses: actions/github-script@v7
+        with:
+          name: rtlmeter-pr-results
+          run-id: ${{ github.event.workflow_run.id }}
+          github-tokne: ${{ secrets.GITHUB_TOKEN }}
+      - name: Comment on PR
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          ls -la
+          cat report.txt
+          gh pr --repo ${{ github.repository }} comment ${{ github.event.workflow_run.pull_requests[0].number }} --body-file report.txt