Add deprecated option to CategorySet message and component_categories field

Co-authored-by: Marenz <[email protected]>

Author: Copilot

RELEASE_NOTES.md

@@ -14,6 +14,8 @@
 
 ## Upgrading
 
+- The `CategorySet` message and `component_categories` field in `TargetComponents` are now properly marked as deprecated in the protobuf schema using the `deprecated` option. Code generators will now emit deprecation warnings when these deprecated elements are used. Use `CategoryTypeSet` and `component_categories_types` instead.
+
 <!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
 
 ## New Features

proto/frequenz/api/dispatch/v1/dispatch.proto

@@ -391,6 +391,7 @@ message TargetComponents {
 
   // Deprecated: Use `CategoryTypeSet` instead
   message CategorySet {
+    option deprecated = true;
     // Set of component categories
     repeated frequenz.api.common.v1alpha8.microgrid.electrical_components
         .ElectricalComponentCategory categories = 1;
@@ -437,7 +438,7 @@ message TargetComponents {
     // Deprecated: Component categories
     // Use `CategoryTypeSet` instead
     // In future versions, this field will be removed.
-    CategorySet component_categories = 2;
+    CategorySet component_categories = 2 [deprecated = true];
 
     // Component categories with optional types
     CategoryTypeSet component_categories_types = 3;