Add git.DIFF_RENAME_SIMILARITY_THRESHOLD option (#36164)

Make the threshold value passed to `git diff --find-renames` configurable

services/gitdiff/git_diff_tree.go

@@ -15,6 +15,7 @@ import (
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/git/gitcmd"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
 )
 
 type DiffTree struct {
@@ -56,7 +57,9 @@ func runGitDiffTree(ctx context.Context, gitRepo *git.Repository, useMergeBase b
 		return nil, err
 	}
 
-	cmd := gitcmd.NewCommand("diff-tree", "--raw", "-r", "--find-renames", "--root")
+	cmd := gitcmd.NewCommand("diff-tree", "--raw", "-r", "--root").
+		AddOptionFormat("--find-renames=%s", setting.Git.DiffRenameSimilarityThreshold)
+
 	if useMergeBase {
 		cmd.AddArguments("--merge-base")
 	}