Libraries: Use AK::Variant default initialization where appropriate

Author: https://github.com/BenWiederhake
Commit: 32e98d0924
Pull-request: https://github.com/SerenityOS/serenity/pull/10154
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibJS/Parser.cpp

@@ -2180,7 +2180,7 @@ NonnullRefPtr<VariableDeclaration> Parser::parse_variable_declaration(bool for_l
 
     NonnullRefPtrVector<VariableDeclarator> declarations;
     for (;;) {
-        Variant<NonnullRefPtr<Identifier>, NonnullRefPtr<BindingPattern>, Empty> target { Empty() };
+        Variant<NonnullRefPtr<Identifier>, NonnullRefPtr<BindingPattern>, Empty> target {};
         if (match_identifier()) {
             auto identifier_start = push_start();
             auto name = consume_identifier().value();