ci: try to simplify posting comments

Author: michalrus

.github/workflows/std.yml

@@ -178,17 +178,9 @@ jobs:
             nix run -L ".#[email protected]" | tee k8s-plan.diff
           '
       - name: Post Comment on the PR
-        uses: actions/github-script@v5
-        with:
-          script: |
-            const fs = require('fs');
-            const output = fs.readFileSync('k8s-plan.diff', 'utf8');
-            github.rest.issues.createComment({
-              issue_number: context.issue.number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: "```diff\n" + output + "\n```\n",
-            });
+        run: |
+          prNumber=$(cut -d/ -f1 <<<'${{ github.ref_name }}')
+          gh pr comment "$prNumber" --body "$(sed -e '2i\\n```diff' -e '$a```' k8s-plan.diff)"
 
 
   deploy-to-us: