Switch the shared ghostty-internal.pc Libs: line from -lghostty to a
direct ${libdir}/<file> path, matching what the -static module already
does. The name-per-OS helpers now emit:
shared: ghostty-internal.dll (Windows) / ghostty-internal.so (other)
static: ghostty-internal-static.lib (Windows) / ghostty-internal.a
Direct paths sidestep the GNU-ld -l<name> search template, which
expects libghostty-internal.so/.a on Unix - we drop the lib prefix to
match the ghostty-internal pkg-config module name.
Also update the LipoStep out_name for the macOS universal static
archive to ghostty-internal.a for consistency.
1988ac94d4