bin/gen_release_notes.py: don't fail if "Closes" refers to an MR

Sometimes a tag "Closes:" in a commit may refer to a merge request
instead of an issue. Examples of such commits:

    34319c7d84 "ci/freedreno: disable antichambers trace"
    998122d9c2 "mesa: fix GL_INVALID_OPERATION in glEGLImageTargetTexStorageEXT"

Avoid failing on these by explicitly checking that the URL refers to an
issue

Cc: mesa-stable
Signed-off-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20241>

bin/gen_release_notes.py

@@ -195,7 +195,11 @@ async def parse_issues(commits: str) -> typing.List[str]:
         for line in reversed(out):
             if line.startswith('Closes:'):
                 bug = line.lstrip('Closes:').strip()
-                if bug.startswith('https://gitlab.freedesktop.org/mesa/mesa'):
+                if (bug.startswith('https://gitlab.freedesktop.org/mesa/mesa')
+                    # Avoid parsing "merge_requests" URL. Note that a valid issue
+                    # URL may or may not contain the "/-/" text, so we check if
+                    # the word "issues" is contained in URL.
+                    and '/issues' in bug):
                     # This means we have a bug in the form "Closes: https://..."
                     issues.append(os.path.basename(urllib.parse.urlparse(bug).path))
                 elif ',' in bug: