Downgrade protobuf to 4.21.6

This version should work, as it is the version used in the SDK
v1.0.0-rc5. If we don't do this we introduce an unnecessary dependency
conflict with the SDK.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -2,16 +2,6 @@
 
 ## Summary
 
-<!-- Here goes a general summary of what this release is about -->
+This version downgrades the `protobuf` dependency to 4.21.6.
 
-## Upgrading
-
-<!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
-
-## New Features
-
-<!-- Here goes the main new features and examples or instructions on how to use them -->
-
-## Bug Fixes
-
-<!-- Here goes notable bug fixes that are worth a special mention or explanation -->
+This is the version used in the SDK v1.0.0-rc5, which we imported the code from. If we don't do this we introduce an unnecessary dependency conflict with the SDK.

pyproject.toml

@@ -40,7 +40,7 @@ dependencies = [
   "frequenz-channels == 1.0.0b2",
   "frequenz-client-base >= 0.2.0, < 0.3.0",
   "grpcio >= 1.54.2, < 2",
-  "protobuf >= 4.25.3, < 5",
+  "protobuf >= 4.21.6, < 5",
   "timezonefinder >= 6.2.0, < 7",
   "typing-extensions >= 4.5.0, < 5",
 ]