Tests: Drop old test_io referencing data which isn't included

This should eventually be rewritten to properly test IO features,
but this would be part of a bigger work on adding a proper testing
framework for Godot features.

Fixes #2454.

main/tests/test_main.cpp

@@ -37,7 +37,6 @@
 #include "test_gdscript.h"
 #include "test_gui.h"
 #include "test_image.h"
-#include "test_io.h"
 #include "test_math.h"
 #include "test_oa_hash_map.h"
 #include "test_ordered_hash_map.h"
@@ -57,7 +56,6 @@ const char **tests_get_names() {
 		"render",
 		"oa_hash_map",
 		"gui",
-		"io",
 		"shaderlang",
 		"gd_tokenizer",
 		"gd_parser",
@@ -111,11 +109,6 @@ MainLoop *test_main(String p_test, const List<String> &p_args) {
 	}
 #endif
 
-	if (p_test == "io") {
-
-		return TestIO::test();
-	}
-
 	if (p_test == "shaderlang") {
 
 		return TestShaderLang::test();