Add missing NO_MUTUAL_GUILDS ErrorResponse

[srnyx]

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Changes

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Description

Added missing ErrorResponse NO_MUTUAL_GUILDS for when the currently logged in account tries to message a user that they share no mutual guilds with

Sources:

• https://docs.discord.com/developers/topics/opcodes-and-status-codes#json
• add err code 50278 to docs discord/discord-api-docs#8212
• update error 50278 with more descriptive string discord/discord-api-docs#8244

Apologies for the patch-1 branch name, I started it all in GitHub cause it was easier

[Copilot]

Pull request overview

Adds newly documented Discord API error codes to JDA’s ErrorResponse enum and updates the meaning text for error code 50008 to match current Discord documentation.

Changes:

• Added missing ErrorResponse enum constants for several Discord error codes (stickers/invites/age/entitlements/sku/request/message/user/index/guild uploads/OIDC).
• Updated the meaning string for CANNOT_MESSAGE_VC (50008) to “Cannot send messages in a non-text channel”.