Revert "src: ignore GCC -Wcast-function-type for v8.h"

This reverts commit f21cf45 as this has
now been included in the V8 version being used.

PR-URL: #35758
Refs: v8/v8@f08cbfd
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

src/string_bytes.h

@@ -26,14 +26,7 @@
 
 // Decodes a v8::Local<v8::String> or Buffer to a raw char*
 
-#if (__GNUC__ >= 8) && !defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wcast-function-type"
-#endif
 #include "v8.h"
-#if (__GNUC__ >= 8) && !defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
 #include "env-inl.h"
 
 #include <string>

test/cctest/test_aliased_buffer.cc

@@ -1,11 +1,4 @@
-#if (__GNUC__ >= 8) && !defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wcast-function-type"
-#endif
 #include "v8.h"
-#if (__GNUC__ >= 8) && !defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
 #include "aliased_buffer.h"
 #include "node_test_fixture.h"