Link the commit in pull request report footers (astral-sh#29621)

The report footer renders the commit SHA as code, so it is not
clickable. Link the commit, label it as the revision the results
describe, and separate the footer from the report.

---------

Co-authored-by: zaniebot <242828183+zaniebot@users.noreply.github.com>

Author: zanieb

scripts/publish_pr_report.py

@@ -171,12 +171,13 @@ def render_report(
         contents = (
             f"{contents.rstrip()}\n\n[Download the full report (ZIP)]({report_url})"
         )
+    commit_url = f"https://github.com/{REPOSITORY}/commit/{run['head_sha']}"
     run_url = f"https://github.com/{REPOSITORY}/actions/runs/{run['id']}/attempts/{run['run_attempt']}"
     return (
         f"{report_marker(report)}\n"
         f"<!-- report-run:{run['id']}:{run['run_attempt']} -->\n\n"
-        f"{contents.rstrip()}\n\n"
-        f"[Workflow run]({run_url}) · `{run['head_sha'][:7]}`\n"
+        f"{contents.rstrip()}\n\n---\n\n"
+        f"Results for [{run['head_sha'][:7]}]({commit_url}) · [Workflow run]({run_url})\n"
     )