[light] Use bitmask instead of std::set for color modes (#11348)

esphome/components/api/api_options.proto

@@ -70,4 +70,14 @@ extend google.protobuf.FieldOptions {
     // init(size) before adding elements. This eliminates std::vector template overhead
     // and is ideal when the exact size is known before populating the array.
     optional bool fixed_vector = 50013 [default=false];
+
+    // container_pointer_no_template: Use a non-template container type for repeated fields
+    // Similar to container_pointer, but for containers that don't take template parameters.
+    // The container type is used as-is without appending element type.
+    // The container must have:
+    // - begin() and end() methods returning iterators
+    // - empty() method
+    // Example: [(container_pointer_no_template) = "light::ColorModeMask"]
+    //   generates: const light::ColorModeMask *supported_color_modes{};
+    optional string container_pointer_no_template = 50014;
 }