Fix support data loading with system ICU

modules/text_server_adv/SCsub

@@ -25,6 +25,9 @@ if "svg" in env.module_list:
     # Enable ThorVG static object linking.
     env_text_server_adv.Append(CPPDEFINES=["TVG_STATIC"])
 
+if env["builtin_icu4c"]:
+    env_text_server_adv.Append(CPPDEFINES=["HAVE_ICU_BUILTIN"])
+
 if env["builtin_harfbuzz"]:
     env_harfbuzz = env_modules.Clone()
     env_harfbuzz.disable_warnings()

modules/text_server_adv/text_server_adv.cpp

@@ -434,7 +434,7 @@ bool TextServerAdvanced::_has(const RID &p_rid) {
 bool TextServerAdvanced::_load_support_data(const String &p_filename) {
 	_THREAD_SAFE_METHOD_
 
-#ifdef ICU_STATIC_DATA
+#if defined(ICU_STATIC_DATA) || !defined(HAVE_ICU_BUILTIN)
 	if (!icu_data_loaded) {
 		UErrorCode err = U_ZERO_ERROR;
 		u_init(&err); // Do not check for errors, since we only load part of the data.