test_trust_live: ride out a transient Gitea error while waiting for the dismissal

A dropped connection or a 5xx inside the wait is retried until the
deadline; any other error fails at once (review on #164).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

tests/integration/test_trust_live.py

@@ -5,6 +5,7 @@ and a commit pushed after the approval needs approving again: at once by the
 agent's own check, and by Gitea once it has dismissed the approval."""
 
 import base64
+import re
 import time
 import uuid
 from pathlib import Path
@@ -44,13 +45,29 @@ def wait_for_dismissal(gitea: GiteaClient, repo: str, pr: int) -> None:
     in the push itself, and its merge check counts what isn't dismissed yet.
     A merge tried before that job has run can still go through (#162)."""
     deadline = time.monotonic() + DISMISS_WAIT_S
-    while gitea.approvals(repo, pr):  # dismissed ones aren't listed
+    while True:
+        try:
+            if not gitea.approvals(repo, pr):  # dismissed ones aren't listed
+                return
+        except GiteaError as exc:
+            # A busy Gitea may drop a call or answer 5xx; ask again. Anything
+            # else, such as a 4xx, is a real failure.
+            if not transient(exc) or time.monotonic() > deadline:
+                raise
         assert time.monotonic() < deadline, (
             f"Gitea didn't dismiss the approval within {DISMISS_WAIT_S}s"
         )
         time.sleep(0.5)
 
 
+def transient(exc: GiteaError) -> bool:
+    """A dropped connection or a 5xx: worth asking again."""
+    text = str(exc)
+    return text.startswith("gitea request failed") or bool(
+        re.search(r" returned 5\d\d:", text)
+    )
+
+
 def test_merging_needs_the_operators_approval_of_the_pr_as_it_is(
     tmp_path: Path, live_config: AgentConfig, gitea: GiteaClient
 ) -> None: