Makes ZapAmount viewmodel stable

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/UpdateZapAmountDialog.kt

@@ -60,6 +60,7 @@ import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.Stable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -109,6 +110,7 @@ import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
+@Stable
 class UpdateZapAmountViewModel : ViewModel() {
     var account: Account? = null