fix: correct leaking this

libquassel-protocol/src/main/kotlin/de/justjanne/libquassel/protocol/syncables/StatefulSyncableObject.kt

@@ -39,7 +39,7 @@ abstract class StatefulSyncableObject<T>(
     return result
   }
 
-  override fun state(): T = state.value
-  override fun flow(): Flow<T> = state
+  final override fun state(): T = state.value
+  final override fun flow(): Flow<T> = state
   protected val state = MutableStateFlow(state)
 }

libquassel-protocol/src/test/kotlin/de/justjanne/libquassel/protocol/testutil/mocks/EmptySession.kt

@@ -55,7 +55,7 @@ open class EmptySession : Session {
   override fun removeIdentity(id: IdentityId) = Unit
   override fun identities() = emptySet<Identity>()
 
-  override fun certManager(id: IdentityId) = null
+  override fun certManager(id: IdentityId): CertManager? = null
   override fun certManagers() = emptySet<CertManager>()
 
   override fun rename(className: String, oldName: String, newName: String) = Unit