Add Fixture::for_worktree_path

Author: cruessler

gix-blame/tests/blame.rs

@@ -116,7 +116,10 @@ struct Fixture {
 
 impl Fixture {
     fn new() -> gix_testtools::Result<Fixture> {
-        let worktree_path = fixture_path();
+        Self::for_worktree_path(fixture_path())
+    }
+
+    fn for_worktree_path(worktree_path: PathBuf) -> gix_testtools::Result<Fixture> {
         use gix_ref::store::WriteReflog;
 
         let store = gix_ref::file::Store::at(