Add Close() method to gogitRepository (#8901)

In investigating #7947 it has become clear that the storage component of go-git repositories needs closing.

This PR adds this Close function and adds the Close functions as necessary.

In TransferOwnership the ctx.Repo.GitRepo is closed if it is open to help prevent the risk of multiple open files.

Fixes #7947

modules/git/commit_info_test.go

@@ -77,6 +77,8 @@ func TestEntries_GetCommitsInfo(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 	bareRepo1, err := OpenRepository(bareRepo1Path)
 	assert.NoError(t, err)
+	defer bareRepo1.Close()
+
 	testGetCommitsInfo(t, bareRepo1)
 
 	clonedPath, err := cloneRepo(bareRepo1Path, testReposDir, "repo1_TestEntries_GetCommitsInfo")
@@ -84,6 +86,8 @@ func TestEntries_GetCommitsInfo(t *testing.T) {
 	defer os.RemoveAll(clonedPath)
 	clonedRepo1, err := OpenRepository(clonedPath)
 	assert.NoError(t, err)
+	defer clonedRepo1.Close()
+
 	testGetCommitsInfo(t, clonedRepo1)
 }
 
@@ -101,13 +105,16 @@ func BenchmarkEntries_GetCommitsInfo(b *testing.B) {
 	for _, benchmark := range benchmarks {
 		var commit *Commit
 		var entries Entries
+		var repo *Repository
 		if repoPath, err := cloneRepo(benchmark.url, benchmarkReposDir, benchmark.name); err != nil {
 			b.Fatal(err)
-		} else if repo, err := OpenRepository(repoPath); err != nil {
+		} else if repo, err = OpenRepository(repoPath); err != nil {
 			b.Fatal(err)
 		} else if commit, err = repo.GetBranchCommit("master"); err != nil {
+			repo.Close()
 			b.Fatal(err)
 		} else if entries, err = commit.Tree.ListEntries(); err != nil {
+			repo.Close()
 			b.Fatal(err)
 		}
 		entries.Sort()
@@ -120,5 +127,6 @@ func BenchmarkEntries_GetCommitsInfo(b *testing.B) {
 				}
 			}
 		})
+		repo.Close()
 	}
 }