Trying to install clang13-devel from the Backports repository results in:

:~ -> sudo zypper install clang13-devel
Loading repository data...
Reading installed packages...
Resolving package dependencies...

Problem: nothing provides 'clang-tools >= 13.0.1' needed by the to be installed
clang13-devel-13.0.1-bp155.6.38.x86_64
 Solution 1: do not install clang13-devel-13.0.1-bp155.6.38.x86_64
 Solution 2: break clang13-devel-13.0.1-bp155.6.38.x86_64 by ignoring some of
its dependencies

Choose from above solutions by number or cancel [1/2/c/d/?] (c): ^C

Is there some other repository I am missing?