https://github.com/hub4j/github-api/blob/e14ec3b3677760714cd096ad8157a3e6a6dded65/src/main/java/org/kohsuke/github/GHIssueStateReason.java

https://docs.github.com/en/rest/issues/issues?apiVersion=2022-11-28#update-an-issue

state_reason string or null
Can be one of: completed, not_planned, reopened, null

reopened is supported and should be added.