fix(api): stop leaking private repo metadata after access revocation (#38321) (#38390)

Backport #38321 by @bircni

The `/user/starred` and `/user/subscriptions` endpoints returned private
repositories a user had starred/watched even after their access to those
repositories was revoked, still exposing the repository name,
description and visibility (including later metadata changes).

Private repositories in the starred/watched queries are now gated on the
actor's current access via `AccessibleRepositoryCondition`, so users who
no longer have access no longer receive the metadata. Public
repositories and public-only tokens are unaffected.

Co-authored-by: bircni <bircni@icloud.com>

routers/api/v1/user/star.go

@@ -24,6 +24,7 @@ func getStarredRepos(ctx *context.APIContext, user *user_model.User, private boo
 		ListOptions:    utils.GetListOptions(ctx),
 		StarrerID:      user.ID,
 		IncludePrivate: private,
+		Actor:          user,
 	}
 	opts.ApplyPublicOnly(ctx.PublicOnly)
 

routers/api/v1/user/watch.go

@@ -22,6 +22,7 @@ func getWatchedRepos(ctx *context.APIContext, user *user_model.User, private boo
 		ListOptions:    utils.GetListOptions(ctx),
 		WatcherID:      user.ID,
 		IncludePrivate: private,
+		Actor:          user,
 	}
 	opts.ApplyPublicOnly(ctx.PublicOnly)