Update protobuf monorepo to v4

Author: renovate[bot]

gradle/libs.versions.toml

@@ -32,7 +32,7 @@ mapstruct = "1.6.3"
 micronaut = "4.8.3"
 micronaut-graphql = "4.7.0"
 okhttp = "4.12.0"
-protobuf = "3.25.6"
+protobuf = "4.29.3"
 slugify = "3.0.7"
 error-prone = "2.36.0"
 icu4j = "76.1"