Remove a dependency override. (#560)

diff --git a/pubspec.yaml b/pubspec.yaml
index 13a2144..dd0e98a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -44,4 +44,3 @@
 
 dependency_overrides:
   scheduled_test: '^0.12.5'
-  stack_trace: {path: ../stack_trace}