Revert code that fails with ASAN

Author: ksss

ext/rbs_extension/main.c

@@ -466,10 +466,6 @@ void Init_rbs_extension(void) {
 #ifdef HAVE_RB_EXT_RACTOR_SAFE
     rb_ext_ractor_safe(true);
 #endif
-    // ASAN test: intentional heap buffer overflow to verify ASAN is working
-    volatile char *test_ptr = malloc(10);
-    test_ptr[10] = 'A'; // Out of bounds write - this will be caught by ASAN
-
     rbs__init_constants();
     rbs__init_location();
     rbs__init_parser();