Gitea watched repositories API disclosure after access revocation

`GET /api/v1/user/subscriptions` returned the metadata of every repository a user was watching without checking that the user still had access to it. A user who watched a private repository while having access, and later lost it, for example through a team permission downgrade, could still read its name, description, clone URLs, owner and counters. The issue was fixed in 1.27.0 and 28.0.0 and disclosed with 28.2.0.