Add write check for creating Commit status (#20332) (#20334)

- Backport #20332
  - Add write code checks for creating new commit status
  - Regression from #5314
  - Resolves #20331

Author: Gusted

Diff for: routers/api/v1/api.go

@@ -954,7 +954,7 @@ func Routes(sessioner func(http.Handler) http.Handler) *web.Route {
 				}, mustAllowPulls, reqRepoReader(unit.TypeCode), context.ReferencesGitRepo(false))
 				m.Group("/statuses", func() {
 					m.Combo("/{sha}").Get(repo.GetCommitStatuses).
-						Post(reqToken(), bind(api.CreateStatusOption{}), repo.NewCommitStatus)
+						Post(reqToken(), reqRepoWriter(unit.TypeCode), bind(api.CreateStatusOption{}), repo.NewCommitStatus)
 				}, reqRepoReader(unit.TypeCode))
 				m.Group("/commits", func() {
 					m.Get("", repo.GetAllCommits)