Fixed crate_universe lockfile checks for crates_repository rule (#1468)

diff --git a/crate_universe/private/generate_utils.bzl b/crate_universe/private/generate_utils.bzl
index 5b6bd77..469cb22 100644
--- a/crate_universe/private/generate_utils.bzl
+++ b/crate_universe/private/generate_utils.bzl
@@ -322,7 +322,7 @@
             return True
 
     # If a deterministic lockfile was not added then always repin
-    if not lockfile_path or lockfile_path.exists:
+    if not lockfile_path:
         return True
 
     # Run the binary to check if a repin is needed