Blizzard has updated one of their internal servers with the first 11.0.5 build, build 56036.
Note that this build is encrypted and we don't have access to it, so we can't datamine its contents.
Based on the WoW 2024 Roadmap, we should expect 11.0.5 to drop around mid-to-end of Fall, so October/early-November, since this is the patch with the 20th Anniversary celebration content.