deps: fix V8 compiler error with clang++-11

Fixes: #33040

		  error: type 'antlr4::tree::TerminalNode *' cannot be narrowed to 'bool'
			  in initializer list [-Wc++11-narrowing]
			ParameterList result{{}, {}, context->VARARGS(), {}};

Occurs twice:
		../../deps/v8/src/torque/ast-generator.cc:123:32:
		../../deps/v8/src/torque/ast-generator.cc:144:32:

common.gypi

@@ -33,7 +33,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.56',
+    'v8_embedder_string': '-node.57',
 
     # Enable disassembler for `--print-code` v8 options
     'v8_enable_disassembler': 1,

deps/v8/src/torque/ast-generator.cc

@@ -120,7 +120,7 @@ Statement* AstGenerator::GetOptionalHelperBody(
 
 antlrcpp::Any AstGenerator::visitParameterList(
     TorqueParser::ParameterListContext* context) {
-  ParameterList result{{}, {}, context->VARARGS(), {}};
+  ParameterList result{{}, {}, context->VARARGS() != nullptr, {}};
   if (context->VARARGS()) {
     result.arguments_variable = context->IDENTIFIER()->getSymbol()->getText();
   }
@@ -141,7 +141,7 @@ antlrcpp::Any AstGenerator::visitTypeList(
 
 antlrcpp::Any AstGenerator::visitTypeListMaybeVarArgs(
     TorqueParser::TypeListMaybeVarArgsContext* context) {
-  ParameterList result{{}, {}, context->VARARGS(), {}};
+  ParameterList result{{}, {}, context->VARARGS() != nullptr, {}};
   result.types.reserve(context->type().size());
   for (auto* type : context->type()) {
     result.types.push_back(GetType(type));