This reverts commit c69ec700adec315b3daa55742f2ef655242fa297, which has been
obsolete since commit dec63221d56e because the clang-format style was added
in version 18.
The current CI doesn't use the latest clang-format and fails most
clang-format patches on the code formatting check. This patch
temporarily removes the clang-format style from the .clang-format
files.