[Bazel] Fix gen_reflections for flatbuffers_ts_library (#7981)

If you used flatbuffers_ts_library with gen_reflections = True then it
attempted to use the flat-file compiler rather than flatc itself.

Co-authored-by: Derek Bailey <derekbailey@google.com>

reflection/ts/BUILD.bazel

@@ -10,5 +10,6 @@ genrule(
 flatbuffer_ts_library(
     name = "reflection_ts_fbs",
     srcs = [":reflection.fbs"],
+    gen_reflections = True,
     visibility = ["//visibility:public"],
 )