Add a new assertion macro ut_asserteq_regex() that checks if a string matches a regular expression pattern using the SLRE library. This is useful for tests where exact string-matching is difficult, such as when output contains line numbers or other variable content. Use a helper function ut_check_regex() to avoid including slre.h in the header. Co-developed-by: Claude <noreply@anthropic.com> Signed-off-by: Simon Glass <simon.glass@canonical.com>