docker: install libclang-rt-dev on LLVM 14+

Debian recently changed the packaging of the compiler runtime files, which can result in cryptic build failures when building kernels that contain an older version of CFI, such as the one present in downstream Android trees. Dumping the call to clang from the try-run macro reveals:

  clang: error: missing sanitizer ignorelist: '/usr/lib/llvm-15/lib/clang/15.0.7/share/cfi_ignorelist.txt'

These files are now in the libclang-rt-dev package. Install those packages to gain these files so everything continues to build properly.

Link: https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/commit/d24f4d88f13021fca6afe9ce9d087c71362af2cf

NOTE: This has a soft dependency on !289 (merged) due to the shift of clang-nightly to 17, so the clang-nightly tests currently fail. Everything else appears to work for me locally. Additionally, there is no base libclang-rt-dev for clang-nightly so it does have the current number in the package. Hopefully this is okay.