chore(ci): add faster ament_cmake to build_depends.repos (autowarefoundation#7317)

Signed-off-by: Ryohsuke Mitsudome <ryohsuke.mitsudome@tier4.jp>

Author: mitsudome-r

build_depends.repos

@@ -41,3 +41,7 @@ repositories:
     type: git
     url: https://github.com/tier4/glog.git
     version: v0.6.0_t4-ros
+  universe/external/ament_cmake: # TODO(mitsudome-r): remove when https://github.com/ament/ament_cmake/pull/448 is merged
+    type: git
+    url: https://github.com/autowarefoundation/ament_cmake.git
+    version: feat/faster_ament_libraries_deduplicate