Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`, now with "east const" enforcement.
Use `clang-format` version 18.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Issue: #26123
Set the close-on-exec flag to prevent the jobserver FIFO file
descriptor from leaking to subprocesses spawned by `ctest`.
This leak is usually harmless, but can cause `make test -jN` to hang
at the end of the build if a test leaves a background process running
with the jobserver FIFO file descriptor open.
Fixes: #26027