Remove commit status running and warning to align GitHub (#25839)

Fix #25776. Close #25826.

In the discussion of #25776, @wolfogre's suggestion was to remove the
commit status of `running` and `warning` to keep it consistent with
github.

references:
-
https://docs.github.com/en/rest/commits/statuses?apiVersion=2022-11-28#about-commit-statuses


## ⚠️ BREAKING ⚠️

So the commit status of Gitea will be consistent with GitHub, only
`pending`, `success`, `error` and `failure`, while `warning` and
`running` are not supported anymore.

---------

Co-authored-by: Jason Song <i@wolfogre.com>

tests/integration/pull_status_test.go

@@ -52,7 +52,6 @@ func TestPullCreate_CommitStatus(t *testing.T) {
 			api.CommitStatusPending,
 			api.CommitStatusError,
 			api.CommitStatusFailure,
-			api.CommitStatusWarning,
 			api.CommitStatusSuccess,
 		}
 
@@ -61,7 +60,6 @@ func TestPullCreate_CommitStatus(t *testing.T) {
 			api.CommitStatusSuccess: "octicon-check",
 			api.CommitStatusError:   "gitea-exclamation",
 			api.CommitStatusFailure: "octicon-x",
-			api.CommitStatusWarning: "gitea-exclamation",
 		}
 
 		testCtx := NewAPITestContext(t, "user1", "repo1", auth_model.AccessTokenScopeWriteRepository)