[Robot] Add missing json error (#2601)

* Add 30056, 50091, 50144, 50145 Error codes

* Apply suggestions from code review

Co-authored-by: Misha133 <61027276+Misha-133@users.noreply.github.com>

---------

Co-authored-by: Discord.Net Robot <robot@elons.sweatshop.stop>
Co-authored-by: Casmir <68127614+csmir@users.noreply.github.com>
Co-authored-by: Misha133 <61027276+Misha-133@users.noreply.github.com>

src/Discord.Net.Core/DiscordErrorCode.cs

@@ -103,6 +103,7 @@ public enum DiscordErrorCode
         MaximumNumberOfEditsReached = 30046,
         MaximumNumberOfPinnedThreadsInAForumChannelReached = 30047,
         MaximumNumberOfTagsInAForumChannelReached = 30048,
+        MaximumNumberOfPremiumEmojisReached = 30056,
         MaximumNumberOfWebhooksReached = 30058,
         MaximumNumberOfChannelPermissionOverwritesReached = 30060,
         TheChannelsForThisGuildAreTooLarge = 30061,
@@ -176,12 +177,15 @@ public enum DiscordErrorCode
         InvalidThreadNotificationSettings = 50084,
         BeforeValueEarlierThanThreadCreation = 50085,
         CommunityServerChannelsMustBeTextChannels = 50086,
+        TheEntityTypeOfTheEventIsDifferentFromTheEntityYouAreTryingToStartTheEventFor = 50091,
         ServerLocaleUnavailable = 50095,
         ServerRequiresMonetization = 50097,
         ServerRequiresBoosts = 50101,
         RequestBodyContainsInvalidJSON = 50109,
         OwnershipCannotBeTransferredToABotUser = 50132,
         FailedToResizeAssetBelowTheMaximumSize = 50138,
+        CannotMixSubscriptionAndNonSubscriptionRolesForAnEmoji = 50144,
+        CannotConvertBetweenPremiumEmojiAndNormalEmoji = 50145,
         UploadedFileNotFound = 50146,
         FeatureInProcessOfRollingOut = 50155,
         MissingPermissionToSendThisSticker = 50600,