fix(pr): return statuses for head commit

Based on the code, it doesn't make much sense to fetch »all« commits to
just take the last one, i.e., the head commit of the PR. Therefore
switch to using the head commit property directly instead of list of all
commits that's not even used.

Signed-off-by: Matej Focko <[email protected]>

Author: mfocko

ogr/services/base.py

@@ -79,7 +79,10 @@ def search(
         )
 
     def get_statuses(self) -> Union[list[CommitFlag], Iterable[CommitFlag]]:
-        commit = self.get_all_commits()[-1]
+        # [NOTE] Is there any reason we fetch all commits, instead of using the
+        # head commit on the PR?
+        # commit = self.get_all_commits()[-1]
+        commit = self.head_commit
         return self.target_project.get_commit_statuses(commit)