Adds missing return type to collect_traces function

returns/primitives/tracing.py

@@ -1,13 +1,13 @@
 import types
 from contextlib import contextmanager
 from inspect import FrameInfo, stack
-from typing import List, Optional
+from typing import Iterator, List, Optional
 
 from returns.result import _Failure
 
 
 @contextmanager
-def collect_traces():
+def collect_traces() -> Iterator[None]:
     """
     Context Manager/Decorator to active traces collect to the Failures.
 

typesafety/test_primitives/test_tracing/test_collect_traces.yml

@@ -0,0 +1,13 @@
+- case: collect_traces_context_manager_return_type_hint
+  disable_cache: true
+  main: |
+    from returns.primitives.tracing import collect_traces
+
+    reveal_type(collect_traces)  # N: Revealed type is 'def () -> contextlib._GeneratorContextManager[None]'
+
+- case: collect_traces_context_manager_return_type
+  disable_cache: true
+  main: |
+    from returns.primitives.tracing import collect_traces
+
+    reveal_type(collect_traces())  # N: Revealed type is 'contextlib._GeneratorContextManager[None]'