Simplify how git repositories are opened (#28937)

## Purpose
This is a refactor toward building an abstraction over managing git
repositories.
Afterwards, it does not matter anymore if they are stored on the local
disk or somewhere remote.

## What this PR changes
We used `git.OpenRepository` everywhere previously.
Now, we should split them into two distinct functions:

Firstly, there are temporary repositories which do not change:

```go
git.OpenRepository(ctx, diskPath)
```

Gitea managed repositories having a record in the database in the
`repository` table are moved into the new package `gitrepo`:

```go
gitrepo.OpenRepository(ctx, repo_model.Repo)
```

Why is `repo_model.Repository` the second parameter instead of file
path?
Because then we can easily adapt our repository storage strategy.
The repositories can be stored locally, however, they could just as well
be stored on a remote server.

## Further changes in other PRs
- A Git Command wrapper on package `gitrepo` could be created. i.e.
`NewCommand(ctx, repo_model.Repository, commands...)`. `git.RunOpts{Dir:
repo.RepoPath()}`, the directory should be empty before invoking this
method and it can be filled in the function only. #28940
- Remove the `RepoPath()`/`WikiPath()` functions to reduce the
possibility of mistakes.

---------

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

2 files changed, 5 insertions, 3 deletions

diff --git a/services/migrations/gitea_uploader.go b/services/migrations/gitea_uploader.go
index 5a4392c667..7b21d9f4d2 100644
--- a/services/migrations/gitea_uploader.go
+++ b/services/migrations/gitea_uploader.go
@@ -21,6 +21,7 @@ import (
 	user_model "code.gitea.io/gitea/models/user"
 	base_module "code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/label"
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
@@ -139,7 +140,7 @@ func (g *GiteaLocalUploader) CreateRepo(repo *base.Repository, opts base.Migrate
 	if err != nil {
 		return err
 	}
-	g.gitRepo, err = git.OpenRepository(g.ctx, r.RepoPath())
+	g.gitRepo, err = gitrepo.OpenRepository(g.ctx, r)
 	return err
 }
 
diff --git a/services/migrations/gitea_uploader_test.go b/services/migrations/gitea_uploader_test.go
index 4ec0361dfb..c8102c6b8b 100644
--- a/services/migrations/gitea_uploader_test.go
+++ b/services/migrations/gitea_uploader_test.go
@@ -19,6 +19,7 @@ import (
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 	base "code.gitea.io/gitea/modules/migration"
@@ -249,7 +250,7 @@ func TestGiteaUploadUpdateGitForPullRequest(t *testing.T) {
 		Author:    &signature,
 		Message:   "Initial Commit",
 	}))
-	fromGitRepo, err := git.OpenRepository(git.DefaultContext, fromRepo.RepoPath())
+	fromGitRepo, err := gitrepo.OpenRepository(git.DefaultContext, fromRepo)
 	assert.NoError(t, err)
 	defer fromGitRepo.Close()
 	baseSHA, err := fromGitRepo.GetBranchCommitID(baseRef)
@@ -292,7 +293,7 @@ func TestGiteaUploadUpdateGitForPullRequest(t *testing.T) {
 		Author:    &signature,
 		Message:   "branch2 commit",
 	}))
-	forkGitRepo, err := git.OpenRepository(git.DefaultContext, forkRepo.RepoPath())
+	forkGitRepo, err := gitrepo.OpenRepository(git.DefaultContext, forkRepo)
 	assert.NoError(t, err)
 	defer forkGitRepo.Close()
 	forkHeadSHA, err := forkGitRepo.GetBranchCommitID(forkHeadRef)