fix: /retest does not support security-committer-identity and security-suspicious-paths

[myakove]

Problem

/retest security-committer-identity and /retest security-suspicious-paths return "No security-committer-identity configured for this repository" even when security checks are enabled and working.

Example: RedHatQE/mtv-api-tests#549

Root Cause

_current_pull_request_supported_retest in webhook_server/libs/github_api.py (line 1391) builds the list of retestable checks but does not include security check names (security-committer-identity, security-suspicious-paths).

When a user types /retest security-committer-identity, the name is not in the supported list, so it falls into _not_supported_retests and the user gets the error message.

Additionally, run_retests in webhook_server/libs/handlers/runner_handler.py (line 1947) does not have security check functions in its dispatch map.

Fix

1. _current_pull_request_supported_retest — add security checks when enabled:

   • security_committer_identity_check is True → append SECURITY_COMMITTER_IDENTITY_STR
   • security_suspicious_paths is non-empty → append SECURITY_SUSPICIOUS_PATHS_STR

2. run_retests function map — add security runners with lambda wrappers (security methods don't take pull_request param)

Done

• Add security checks to _current_pull_request_supported_retest
• Add security runners to run_retests dispatch map
• Add tests for retesting security checks
• Update welcome message to show security checks as retestable