The old, not longer needed, toolchain file should be deleted

[ClausKlein]

bash-5.3$ tree etc/
etc/
├── ci-clang-toolchain.cmake
├── clang-16-toolchain.cmake
├── clang-17-toolchain.cmake
├── clang-18-toolchain.cmake
├── clang-19-toolchain.cmake
├── clang-flags.cmake
├── clang-toolchain.cmake
├── gcc-11-toolchain.cmake
├── gcc-12-toolchain.cmake
├── gcc-13-toolchain.cmake
├── gcc-14-toolchain.cmake
├── gcc-flags.cmake
├── gcc-toolchain.cmake
├── llvm-16-toolchain.cmake
├── llvm-master-toolchain.cmake
├── llvm-toolchain.cmake
└── toolchain.cmake

1 directory, 17 files
bash-5.3$