Bug#1022551: llvm-15's cmake now requires clang-tools-15, clang-tidy-15, clangd-15, even if unused

[Matthias Klose]

Control: reopen -1
Control: found -1 15.0.3-1

> it is fixed in experimental
no, it is not.  As said on IRC, there's a reproducer to build cvise 2.6.0-1 
without the extra dependencies

  clang-tools-15, clang-tidy-15, clangd-15

and the build fails.