Gitea: GHSA-8fwc-qjw5-rvgp ClearRepoWatches fix not applied to API EditRepo path — sister code path retains stale watches on public->private

Summary GHSA-8fwc-qjw5-rvgp "Gitea may send release notification emails for private repositories to users whose access has been revoked", fix in PR 36319 / commit 8a98ac22 added repomodel.ClearRepoWatches as a defense for the state transition public→private. The cleanup was wired into...