Use the type RefName for all the needed places and fix pull mirror sync bugs (#24634)

This PR replaces all string refName as a type `git.RefName` to make the
code more maintainable.

Fix #15367
Replaces #23070 
It also fixed a bug that tags are not sync because `git remote --prune
origin` will not remove local tags if remote removed.

We in fact should use `git fetch --prune --tags origin` but not `git
remote update origin` to do the sync.

Some answer from ChatGPT as ref.

> If the git fetch --prune --tags command is not working as expected,
there could be a few reasons why. Here are a few things to check:
> 
>Make sure that you have the latest version of Git installed on your
system. You can check the version by running git --version in your
terminal. If you have an outdated version, try updating Git and see if
that resolves the issue.
> 
>Check that your Git repository is properly configured to track the
remote repository's tags. You can check this by running git config
--get-all remote.origin.fetch and verifying that it includes
+refs/tags/*:refs/tags/*. If it does not, you can add it by running git
config --add remote.origin.fetch "+refs/tags/*:refs/tags/*".
> 
>Verify that the tags you are trying to prune actually exist on the
remote repository. You can do this by running git ls-remote --tags
origin to list all the tags on the remote repository.
> 
>Check if any local tags have been created that match the names of tags
on the remote repository. If so, these local tags may be preventing the
git fetch --prune --tags command from working properly. You can delete
local tags using the git tag -d command.

---------

Co-authored-by: delvh <dev.lh@web.de>

modules/notification/base/null.go

@@ -10,6 +10,7 @@ import (
 	packages_model "code.gitea.io/gitea/models/packages"
 	repo_model "code.gitea.io/gitea/models/repo"
 	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/repository"
 )
 
@@ -161,11 +162,11 @@ func (*NullNotifier) NotifyPushCommits(ctx context.Context, pusher *user_model.U
 }
 
 // NotifyCreateRef notifies branch or tag creation to notifiers
-func (*NullNotifier) NotifyCreateRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refType, refFullName, refID string) {
+func (*NullNotifier) NotifyCreateRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refFullName git.RefName, refID string) {
 }
 
 // NotifyDeleteRef notifies branch or tag deletion to notifiers
-func (*NullNotifier) NotifyDeleteRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refType, refFullName string) {
+func (*NullNotifier) NotifyDeleteRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refFullName git.RefName) {
 }
 
 // NotifyRenameRepository places a place holder function
@@ -181,11 +182,11 @@ func (*NullNotifier) NotifySyncPushCommits(ctx context.Context, pusher *user_mod
 }
 
 // NotifySyncCreateRef places a place holder function
-func (*NullNotifier) NotifySyncCreateRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refType, refFullName, refID string) {
+func (*NullNotifier) NotifySyncCreateRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refFullName git.RefName, refID string) {
 }
 
 // NotifySyncDeleteRef places a place holder function
-func (*NullNotifier) NotifySyncDeleteRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refType, refFullName string) {
+func (*NullNotifier) NotifySyncDeleteRef(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, refFullName git.RefName) {
 }
 
 // NotifyRepoPendingTransfer places a place holder function