Updated BUILD.bazel with respect to moving CLI11.hpp

Author: jajhall

BUILD.bazel

@@ -121,7 +121,7 @@ cc_library(
 cc_library(
     name = "highs-runtime-opts",
     hdrs = [
-        "app/CLI11.hpp",
+        "extern/CLI11.hpp",
         "app/HighsRuntimeOptions.h",
     ],
     visibility = ["//visibility:public"],