Incorrect member_count in THEAD_MEMBER_UPDATE

[GnomedDev]

Description

Running my 36k guild bot, infrequently I get warnings to the tune of

[serenity::gateway::ws]: Err deserializing text: Json(Error("invalid value: integer -1, expected u64", line: 0, column: 0)); text: {"t":"THREAD_MEMBERS_UPDATE","s":....,"op":0,"d":{"removed_member_ids":["..."],"member_count":-1,"id":"...","guild_id":"..."}}

causing issues due to the library I'm using using an unsigned integer to represent this.

Steps to Reproduce

Run a bot until you get it, no clue how it is actually triggered

Expected Behavior

Unsigned integer less than 50

Current Behavior

Signed integer -1, sometimes above 256 (which caused issues with representing it with a u8)

Screenshots/Videos

No response

Client and System Information

GnomedDev/serenity@personal