src: fix -Wreturn-stack-address error

src: fix -Wreturn-stack-address error · nodejs/node@440d4f4

Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,7 @@ std::optional<std::string_view> ConfigReader::GetDataFromArgs(`
`23`	`23`	`} else if (it->starts_with(flag_path)) {`
`24`	`24`	`// Case: "--experimental-config-file=foo"`
`25`	`25`	`if (it->size() > flag_path.size() && (*it)[flag_path.size()] == '=') {`
`26`		`-return it->substr(flag_path.size() + 1);`
	`26`	`+return std::string_view(*it).substr(flag_path.size() + 1);`
`27`	`27`	`}`
`28`	`28`	`} else if (*it == default_file \|\| it->starts_with(default_file)) {`
`29`	`29`	`has_default_config_file = true;`