fix: before_tool_call hook double-fires with abort signal (#16852)

Merged via /review-pr -> /prepare-pr -> /merge-pr.

Prepared head SHA: 6269d617f3
Co-authored-by: sreuter <550246+sreuter@users.noreply.github.com>
Co-authored-by: obviyus <22031114+obviyus@users.noreply.github.com>
Reviewed-by: @obviyus

src/agents/pi-tools.before-tool-call.ts

@@ -227,7 +227,7 @@ export function wrapToolWithBeforeToolCallHook(
   };
   Object.defineProperty(wrappedTool, BEFORE_TOOL_CALL_WRAPPED, {
     value: true,
-    enumerable: false,
+    enumerable: true,
   });
   return wrappedTool;
 }