fix(gitFs): clean before changing branch

lib/platform/git/storage.js

@@ -265,6 +265,7 @@ class Storage {
     ) {
       try {
         await git.reset('hard');
+        await git.raw(['clean', '-fd']);
         await git.checkout(['-B', branchName, 'origin/' + parentBranch]);
         for (const file of files) {
           await fs.writeFile(join(cwd, file.name), Buffer.from(file.contents));