fix(alpha): rollback to older commit (#3832)

snapshots/default.json

@@ -6,7 +6,7 @@
     "commit": "d404ec3"
   },
   "alpha-nvim": {
-    "commit": "d5fdeb2"
+    "commit": "21a0f25"
   },
   "bigfile.nvim": {
     "commit": "c1bad34"