23.10 will be EOL mid next year, so a bump is needed before then for the master
branch (and possibly the 26.x
branch).
Doing the bump now is fine, because the clang version is pinned to 17 inside the CI tasks. So a default clang version change in the system image should not affect the tasks. Once clang-18 is available and the default in April next year (https://discourse.ubuntu.com/t/noble-numbat-release-schedule/35649#planned-and-potentially-disruptive-archive-wide-activities-2), the pinned version could be bumped (for CI tasks that require a pin, like tidy), or the pin can be removed (for CI tasks that usually do not require a pin, like fuzz or the sanitizers).