fix: add bevdet_vendor dependency in build_depends.repos

Signed-off-by: liu cui <cynthia.liu@autocore.ai>

Author: cyn-liu

build_depends.repos

@@ -58,3 +58,7 @@ repositories:
     type: git
     url: https://github.com/autowarefoundation/ament_cmake.git
     version: feat/faster_ament_libraries_deduplicate
+  universe/external/bevdet_vendor:
+    type: git
+    url: https://github.com/autowarefoundation/bevdet_vendor.git
+    version: bevdet_vendor-ros2