Fix Renovate configuration to match zizmor pattern

- Changed from ratchet format to proper Renovate datasource format
- Uses 'datasource=github-releases depName=trufflesecurity/trufflehog'
- Matches the pattern used in shared-workflows/reusable-zizmor.yml
- Renovate will now properly track TruffleHog GitHub releases

Author: isaiah-grafana

.github/workflows/reusable-trufflehog.yml

@@ -25,7 +25,8 @@ permissions:
   checks: write
 
 env:
-  TRUFFLEHOG_VERSION: 3.82.13 # ratchet:trufflesecurity/[email protected]
+  # renovate: datasource=github-releases depName=trufflesecurity/trufflehog
+  TRUFFLEHOG_VERSION: 3.82.13
 
 jobs:
   trufflehog-scan: