Collaborator trust model should trust collaborators (#18539) (#18557)

Backport #18539

There was an unintended regression in #17917 which leads to only
repository admin commits being trusted. This PR restores the old logic.

Fix #18501

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/commit.go

@@ -18,7 +18,7 @@ func ConvertFromGitCommit(commits []*git.Commit, repo *repo_model.Repository) []
 			user_model.ValidateCommitsWithEmails(commits),
 			repo.GetTrustModel(),
 			func(user *user_model.User) (bool, error) {
-				return IsUserRepoAdmin(repo, user)
+				return IsOwnerMemberCollaborator(repo, user.ID)
 			},
 		),
 		repo,