major(github-exporter): raised chart version to 13.0.0

Author: GitHub Actions

stable/github-exporter/Chart.yaml

@@ -25,4 +25,4 @@ name: github-exporter
 sources:
 - https://github.com/promhippie/github_exporter
 type: application
-version: 12.6.0
+version: 13.0.0