Update CONTRIBUTING.md

Author: mbg

CONTRIBUTING.md

@@ -122,7 +122,7 @@ To deprecate an older version of the Action:
    - Implement an Actions warning for customers using the deprecated version.
 1. Wait for the deprecation period to pass.
 1. Upgrade the Actions warning for customers using the deprecated version to a non-fatal error, and mention that this version of the Action is no longer supported.
-1. Make a PR to bump the `OLDEST_SUPPORTED_MAJOR_VERSION` in [releases.ini](.github/releases.ini).  Once this PR is merged, the release process will no longer backport changes to the deprecated release version.
+1. Make a PR to bump the `OLDEST_SUPPORTED_MAJOR_VERSION` in [config.ts](pr-checks/config.ts).  Once this PR is merged, the release process will no longer backport changes to the deprecated release version.
 
 ## Resources