build: unbreak --with-intl=system-icu build

Include directories are configured by the tools/icu/icu-*.gyp files.
The v8.gyp file doesn't need to add them and in fact the way it did
that breaks when building against an external copy of ICU.

Fixes: nodejs#28052

tools/v8_gypfiles/v8.gyp

@@ -393,13 +393,6 @@
             '<(icu_gyp_path):icui18n',
             '<(icu_gyp_path):icuuc',
           ],
-          'direct_dependent_settings': {
-            'include_dirs': [
-              '<(icu_path)/source/common',
-              '<(icu_path)/source/i18n',
-              '<(icu_path)/source/tools/toolutil',
-            ],
-          },
         }],
       ],
     },  # v8_maybe_icu