add unusual_dm_activity_until to member object (#7650)

Author: ManHatos

docs/resources/guild.mdx

@@ -368,6 +368,7 @@ The fields `id`, `discriminator` and `avatar` are anonymized to prevent abuse.
 | pending?                      | boolean                                                                              | whether the user has not yet passed the guild's [Membership Screening](/docs/resources/guild#membership-screening-object) requirements                                                                                               |
 | permissions?                  | string                                                                               | total permissions of the member in the channel, including overwrites, returned when in the interaction object                                                                                                                        |
 | communication_disabled_until? | ?ISO8601 timestamp                                                                   | when the user's [timeout](https://support.discord.com/hc/en-us/articles/4413305239191-Time-Out-FAQ) will expire and the user will be able to communicate in the guild again, null or a time in the past if the user is not timed out |
+| unusual_dm_activity_until?    | ?ISO8601 timestamp                                                                   | when the member will no longer be marked as having [unusual DM activity](https://support.discord.com/hc/en-us/articles/15946797617431#h_01H5K0YX4XET5E6KP0Q1T9HWNP)                                                                  |
 | avatar_decoration_data?       | ?[avatar decoration data](/docs/resources/user#avatar-decoration-data-object) object | data for the member's guild avatar decoration                                                                                                                                                                                        |
 
 :::info