Move git config/remote to gitrepo package and add global lock to resolve possible conflict when updating repository git config file (#35151)

Partially fix #32018 

`git config` and `git remote` write operations create a temporary file
named `config.lock`. Since these operations are not atomic, they must
not be run in parallel. If two requests attempt to modify the same
repository concurrently—such as during a compare operation—one may fail
due to the presence of an existing `config.lock` file.

In cases where `config.lock` is left behind due to an unexpected program
exit, a global lock mechanism could allow us to safely remove the stale
lock file when a related error is detected. While this behavior is not
yet implemented in this PR, it is planned for a future enhancement.

---------

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/remote.go

@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"strings"
 
-	giturl "code.gitea.io/gitea/modules/git/url"
 	"code.gitea.io/gitea/modules/util"
 )
 
@@ -33,15 +32,6 @@ func GetRemoteAddress(ctx context.Context, repoPath, remoteName string) (string,
 	return result, nil
 }
 
-// GetRemoteURL returns the url of a specific remote of the repository.
-func GetRemoteURL(ctx context.Context, repoPath, remoteName string) (*giturl.GitURL, error) {
-	addr, err := GetRemoteAddress(ctx, repoPath, remoteName)
-	if err != nil {
-		return nil, err
-	}
-	return giturl.ParseGitURL(addr)
-}
-
 // ErrInvalidCloneAddr represents a "InvalidCloneAddr" kind of error.
 type ErrInvalidCloneAddr struct {
 	Host               string