perf(repo): fetch the initial commit instead of pushing it (#39628)

Creating a repository with an initial commit, via `auto_init` or a
template with git content, pushed that commit through receive-pack and
three server-side hooks that do nothing for this internal push except
refresh server info. Fetching it into the bare repository instead makes
such repository creation about 3.7x faster locally (median 790ms to
214ms). E2E tests that create initialized repositories get about
0.2-0.3s faster each.

1. Run `update-server-info` after template content generation, which the
push's `post-receive` hook did before.
2. Remove the now unused `InternalPushingEnvironment` and
`PushOptions.LocalRefName`.

modules/repository/env.go

@@ -28,22 +28,11 @@ const (
 	EnvPusherID          = "GITEA_PUSHER_ID"
 	EnvPusherExtDoerData = "GITEA_PUSHER_EXT_DOER_DATA"
 
-	EnvPRID       = "GITEA_PR_ID"
-	EnvPRIndex    = "GITEA_PR_INDEX" // not used by Gitea at the moment, it is for custom git hooks
-	EnvIsInternal = "GITEA_INTERNAL_PUSH"
-	EnvAppURL     = "GITEA_ROOT_URL"
+	EnvPRID    = "GITEA_PR_ID"
+	EnvPRIndex = "GITEA_PR_INDEX" // not used by Gitea at the moment, it is for custom git hooks
+	EnvAppURL  = "GITEA_ROOT_URL"
 )
 
-// InternalPushingEnvironment returns an os environment to switch off hooks on push
-// It is recommended to avoid using this unless you are pushing within a transaction
-// or if you absolutely are sure that post-receive and pre-receive will do nothing
-// We provide the full pushing-environment for other hook providers
-func InternalPushingEnvironment(doer *user_model.User, repo *repo_model.Repository) []string {
-	return append(PushingEnvironment(doer, repo),
-		EnvIsInternal+"=true",
-	)
-}
-
 // PushingEnvironment returns an os environment to allow hooks to work on push
 func PushingEnvironment(doer *user_model.User, repo *repo_model.Repository) []string {
 	return FullPushingEnvironment(doer, doer, repo, repo.Name, 0, 0)