fix: add missing [[maybe_unused]] to IsEnvSet (#33269)

Co-authored-by: Milan Burda <[email protected]>

shell/app/electron_main_mac.cc

@@ -20,7 +20,7 @@
 
 namespace {
 
-bool IsEnvSet(const char* name) {
+[[maybe_unused]] bool IsEnvSet(const char* name) {
   char* indicator = getenv(name);
   return indicator && indicator[0] != '\0';
 }

shell/app/electron_main_win.cc

@@ -44,7 +44,7 @@ namespace {
 const char kUserDataDir[] = "user-data-dir";
 const char kProcessType[] = "type";
 
-bool IsEnvSet(const char* name) {
+[[maybe_unused]] bool IsEnvSet(const char* name) {
   size_t required_size;
   getenv_s(&required_size, nullptr, 0, name);
   return required_size != 0;