[🐴] Ensure keyboard gets dismissed when leaving screen (#4104)

src/components/dms/MessagesListHeader.tsx

@@ -1,5 +1,5 @@
 import React, {useCallback} from 'react'
-import {TouchableOpacity, View} from 'react-native'
+import {Keyboard, TouchableOpacity, View} from 'react-native'
 import {
   AppBskyActorDefs,
   ModerationCause,
@@ -46,6 +46,7 @@ export let MessagesListHeader = ({
     if (isWeb) {
       navigation.replace('Messages', {})
     } else {
+      Keyboard.dismiss()
       navigation.goBack()
     }
   }, [navigation])