Fix "compilation unit" matching in dwarf-font-lock-keywords

Today I learned that, at least on my system (Fedora 40), the printf
"%#x" format will produce "0" rather than "0x0" when given 0 as an
argument.

This causes dwarf-mode.el to not correctly fontify the very first
"Compilation Unit" line it sees.

This patch adapts dwarf-mode.el.  As always, this patch bumps the
version number for easier installation.

I am checking this in.