GCC 15 error: initializer-string for array of 'char' is too long [-Werror=unterminated-string-initialization]

e.g. https://datawarehouse.cki-project.org/kcidb/builds/redhat:1668091672-x86_64-kernel

Looks like some SSTs will add more room in arrays for \0: https://lore.kernel.org/all/3055183.1739200857@warthog.procyon.org.uk/

Meanwhile, GCC 15 might stop raising it unless c++-compat is enabled: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178

Jira: CKI-6830