Edit: apt --fix-broken install solved the problem.
I got it from apt today, but, mmm...
Preparing to unpack .../00-winehq-stable_11.0.0.0~noble-1_amd64.deb ...
Unpacking winehq-stable (11.0.0.0~noble-1) over (10.0.0.0~noble-1) ...
Preparing to unpack .../01-wine-stable_11.0.0.0~noble-1_amd64.deb ...
Unpacking wine-stable (11.0.0.0~noble-1) over (10.0.0.0~noble-1) ...
dpkg: error processing archive /tmp/apt-dpkg-install-BKWjQD/01-wine-stable_11.0.0.0~noble-1_amd64.deb (--unpack):
trying to overwrite '/opt/wine-stable/bin/wine', which is also in package wine-stable-i386:i386 10.0.0.0~noble-1
dpkg-deb: error: paste subprocess was killed by signal (Broken pipe)
Preparing to unpack .../02-wine-stable-i386_11.0.0.0~noble-1_i386.deb ...
Unpacking wine-stable-i386:i386 (11.0.0.0~noble-1) over (10.0.0.0~noble-1) ...
Preparing to unpack .../03-wine-stable-amd64_11.0.0.0~noble-1_amd64.deb ...
Unpacking wine-stable-amd64 (11.0.0.0~noble-1) over (10.0.0.0~noble-1) ...
After retrying,
The following packages have unmet dependencies.
wine-stable : Depends: wine-stable-i386 (= 10.0.0.0~noble-1)
Depends: wine-stable-amd64 (= 10.0.0.0~noble-1) but 11.0.0.0~noble-1 is installed
winehq-stable : Depends: wine-stable (= 11.0.0.0~noble-1)
Not sure if there's something wrong in the way I installed v10, or something quirky in their installer. I'll investigate further before going for apt --fix-broken install.