deps: Upgrade pigeon to 18.0.1

Done with:
  $ flutter pub upgrade pigeon
  $ dart run pigeon
  $ tools/check --all-files --fix pigeon

The `dart run pigeon` step just ends up printing the command's
CLI help... but first it causes the `pigeon` package's CLI binary
to get rebuilt.  So it serves as a workaround for zulip#622.

android/app/src/main/kotlin/com/zulip/flutter/Notifications.g.kt

@@ -1,5 +1,6 @@
-// Autogenerated from Pigeon (v18.0.0), do not edit directly.
+// Autogenerated from Pigeon (v18.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
+@file:Suppress("UNCHECKED_CAST", "ArrayInDataClass")
 
 package com.zulip.flutter
 
@@ -16,14 +17,14 @@ private fun wrapResult(result: Any?): List<Any?> {
 }
 
 private fun wrapError(exception: Throwable): List<Any?> {
-  if (exception is FlutterError) {
-    return listOf(
+  return if (exception is FlutterError) {
+    listOf(
       exception.code,
       exception.message,
       exception.details
     )
   } else {
-    return listOf(
+    listOf(
       exception.javaClass.simpleName,
       exception.toString(),
       "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)
@@ -65,11 +66,11 @@ data class PendingIntent (
 
 ) {
   companion object {
-    @Suppress("UNCHECKED_CAST")
-    fun fromList(list: List<Any?>): PendingIntent {
-      val requestCode = list[0].let { if (it is Int) it.toLong() else it as Long }
-      val intentPayload = list[1] as String
-      val flags = list[2].let { if (it is Int) it.toLong() else it as Long }
+    @Suppress("LocalVariableName")
+    fun fromList(__pigeon_list: List<Any?>): PendingIntent {
+      val requestCode = __pigeon_list[0].let { num -> if (num is Int) num.toLong() else num as Long }
+      val intentPayload = __pigeon_list[1] as String
+      val flags = __pigeon_list[2].let { num -> if (num is Int) num.toLong() else num as Long }
       return PendingIntent(requestCode, intentPayload, flags)
     }
   }
@@ -81,7 +82,6 @@ data class PendingIntent (
     )
   }
 }
-@Suppress("UNCHECKED_CAST")
 private object AndroidNotificationHostApiCodec : StandardMessageCodec() {
   override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? {
     return when (type) {
@@ -133,7 +133,6 @@ interface AndroidNotificationHostApi {
       AndroidNotificationHostApiCodec
     }
     /** Sets up an instance of `AndroidNotificationHostApi` to handle messages through the `binaryMessenger`. */
-    @Suppress("UNCHECKED_CAST")
     fun setUp(binaryMessenger: BinaryMessenger, api: AndroidNotificationHostApi?, messageChannelSuffix: String = "") {
       val separatedMessageChannelSuffix = if (messageChannelSuffix.isNotEmpty()) ".$messageChannelSuffix" else ""
       run {
@@ -142,20 +141,19 @@ interface AndroidNotificationHostApi {
           channel.setMessageHandler { message, reply ->
             val args = message as List<Any?>
             val tagArg = args[0] as String?
-            val idArg = args[1].let { if (it is Int) it.toLong() else it as Long }
+            val idArg = args[1].let { num -> if (num is Int) num.toLong() else num as Long }
             val channelIdArg = args[2] as String
-            val colorArg = args[3].let { if (it is Int) it.toLong() else it as Long? }
+            val colorArg = args[3].let { num -> if (num is Int) num.toLong() else num as Long? }
             val contentIntentArg = args[4] as PendingIntent?
             val contentTextArg = args[5] as String?
             val contentTitleArg = args[6] as String?
             val extrasArg = args[7] as Map<String?, String?>?
             val smallIconResourceNameArg = args[8] as String?
-            var wrapped: List<Any?>
-            try {
+            val wrapped: List<Any?> = try {
               api.notify(tagArg, idArg, channelIdArg, colorArg, contentIntentArg, contentTextArg, contentTitleArg, extrasArg, smallIconResourceNameArg)
-              wrapped = listOf<Any?>(null)
+              listOf<Any?>(null)
             } catch (exception: Throwable) {
-              wrapped = wrapError(exception)
+              wrapError(exception)
             }
             reply.reply(wrapped)
           }

lib/host/android_notifications.g.dart

@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v18.0.0), do not edit directly.
+// Autogenerated from Pigeon (v18.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 

pubspec.lock

@@ -832,10 +832,10 @@ packages:
     dependency: "direct dev"
     description:
       name: pigeon
-      sha256: be883401d09121c427ed9c5f6e96427787d93d335f55e5e2b0d780a0a22cd561
+      sha256: "20fe4dc59f7f9b8070f8732783fdb474d3d4dcd7674a3252230ec4d4f7070ae3"
       url: "https://pub.dev"
     source: hosted
-    version: "18.0.0"
+    version: "18.0.1"
   platform:
     dependency: transitive
     description: