Remove dependency management for Protobuf Common Protos

Boot doesn't interact with the dependency directly so we should not
manage its version. Instead, we should allow the version that comes
in transitively through gRPC Java to be used instead.

Closes gh-50772

platform/spring-boot-dependencies/build.gradle

@@ -1915,17 +1915,6 @@ bom {
 			releaseNotes("https://qpid.apache.org/releases/qpid-protonj2-{version}/release-notes.html")
 		}
 	}
-	library("Protobuf Common Protos", "2.70.0") {
-		group("com.google.api.grpc") {
-			modules = [
-				"proto-google-common-protos"
-			]
-		}
-		links {
-			github("https://github.com/googleapis/sdk-platform-java")
-			releaseNotes("https://github.com/googleapis/sdk-platform-java/releases/tag/v-{version}")
-		}
-	}
 	library("Protobuf Java", "4.34.2") {
 		group("com.google.protobuf") {
 			bom("protobuf-bom")