chore: remove unused GH Workflows

.github/workflows/backport.yml

@@ -1,19 +0,0 @@
-name: Backport PR to stable
-on:
-  pull_request:
-    branches: [ develop ]
-    types: [ closed ]
-jobs:
-  release_pull_request:
-    if: github.event.pull_request.merged == true && contains(github.event.pull_request.labels.*.name, 'backport')
-    runs-on: ubuntu-latest
-    steps:
-    - name: checkout
-      uses: actions/checkout@v3
-      with:
-        fetch-depth: 0
-    - name: Backport PR by cherry-pick-ing
-      uses: Nathanmalnoury/gh-backport-action@master
-      with:
-        pr_branch: 'stable'
-        github_token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/pr-comment.yml

@@ -1,61 +0,0 @@
-name: Comment on pull request
-on:
-  workflow_run:
-    workflows: ['Build Application']
-    types: [completed]
-jobs:
-  pr_comment:
-    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/github-script@v5
-        with:
-          # This snippet is public-domain, taken from
-          # https://github.com/oprypin/nightly.link/blob/master/.github/workflows/pr-comment.yml
-          script: |
-            async function upsertComment(owner, repo, issue_number, purpose, body) {
-              const {data: comments} = await github.rest.issues.listComments(
-                {owner, repo, issue_number});
-
-              const marker = `<!-- bot: ${purpose} -->`;
-              body = marker + "\n" + body;
-
-              const existing = comments.filter((c) => c.body.includes(marker));
-              if (existing.length > 0) {
-                const last = existing[existing.length - 1];
-                core.info(`Updating comment ${last.id}`);
-                await github.rest.issues.updateComment({
-                  owner, repo,
-                  body,
-                  comment_id: last.id,
-                });
-              } else {
-                core.info(`Creating a comment in issue / PR #${issue_number}`);
-                await github.rest.issues.createComment({issue_number, body, owner, repo});
-              }
-            }
-
-            const {owner, repo} = context.repo;
-            const run_id = ${{github.event.workflow_run.id}};
-
-            const pull_requests = ${{ toJSON(github.event.workflow_run.pull_requests) }};
-            if (!pull_requests.length) {
-              return core.error("This workflow doesn't match any pull requests!");
-            }
-
-            const artifacts = await github.paginate(
-              github.rest.actions.listWorkflowRunArtifacts, {owner, repo, run_id});
-            if (!artifacts.length) {
-              return core.error(`No artifacts found`);
-            }
-            let body = `Download the artifacts for this pull request:\n`;
-            for (const art of artifacts) {
-              body += `\n* [${art.name}.zip](https://nightly.link/${owner}/${repo}/actions/artifacts/${art.id}.zip)`;
-            }
-
-            core.info("Review thread message body:", body);
-
-            for (const pr of pull_requests) {
-              await upsertComment(owner, repo, pr.number,
-                "nightly-link", body);
-            }