fix(triage): use exact host match to satisfy CodeQL

Replace .endswith() with exact set membership check for gitlab
hostnames. CodeQL flagged substring matching as incomplete URL
sanitization, even though urlparse().hostname was already used.

RHCLOUD-47252

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Hyperkid123

.claude/skills/triage/triage.py

@@ -133,7 +133,7 @@ def upstream_repo(repo_name):
         host = parsed.hostname or ""
         if host == "github.com":
             return _parse_repo_path(up), "github"
-        if host.endswith("gitlab.com") or host.endswith("gitlab.cee.redhat.com"):
+        if host in ("gitlab.com", "gitlab.cee.redhat.com"):
             return _parse_repo_path(up), "gitlab"
     except Exception:
         pass