meta: suppress (wrong) warnings by g++

test/entt/meta/meta_data.cpp

@@ -224,8 +224,8 @@ TEST_F(MetaData, Custom) {
 ENTT_DEBUG_TEST_F(MetaDataDeathTest, Custom) {
     using namespace entt::literals;
 
-    ASSERT_DEATH([[maybe_unused]] const int &value = entt::resolve<clazz>().data("i"_hs).custom(), "");
-    ASSERT_DEATH([[maybe_unused]] const char &value = entt::resolve<clazz>().data("j"_hs).custom(), "");
+    ASSERT_DEATH([[maybe_unused]] int value = entt::resolve<clazz>().data("i"_hs).custom(), "");
+    ASSERT_DEATH([[maybe_unused]] char value = entt::resolve<clazz>().data("j"_hs).custom(), "");
 }
 
 TEST_F(MetaData, Const) {

test/entt/meta/meta_func.cpp

@@ -241,8 +241,8 @@ TEST_F(MetaFunc, Custom) {
 ENTT_DEBUG_TEST_F(MetaFuncDeathTest, Custom) {
     using namespace entt::literals;
 
-    ASSERT_DEATH([[maybe_unused]] const int &value = entt::resolve<function>().func("g"_hs).custom(), "");
-    ASSERT_DEATH([[maybe_unused]] const char &value = entt::resolve<function>().func("h"_hs).custom(), "");
+    ASSERT_DEATH([[maybe_unused]] int value = entt::resolve<function>().func("g"_hs).custom(), "");
+    ASSERT_DEATH([[maybe_unused]] char value = entt::resolve<function>().func("h"_hs).custom(), "");
 }
 
 TEST_F(MetaFunc, Const) {

test/entt/meta/meta_type.cpp

@@ -303,8 +303,8 @@ TEST_F(MetaType, Custom) {
 }
 
 ENTT_DEBUG_TEST_F(MetaTypeDeathTest, Custom) {
-    ASSERT_DEATH([[maybe_unused]] const int &value = entt::resolve<clazz>().custom(), "");
-    ASSERT_DEATH([[maybe_unused]] const char &value = entt::resolve<base>().custom(), "");
+    ASSERT_DEATH([[maybe_unused]] int value = entt::resolve<clazz>().custom(), "");
+    ASSERT_DEATH([[maybe_unused]] char value = entt::resolve<base>().custom(), "");
 }
 
 TEST_F(MetaType, RemovePointer) {