packaging: adjust pkg-config files after the rust-monocrate changes

Since lix-doc is no longer a separate library, the pkg-config files were broken
for static builds. Adjust them to refer to the new monocrate library instead.

Actually, since the monocrate library is static in all cases it needs to be
linked explicitly even when everything else is linked dynamically. I assume
this only doesn't break the dynamic nix-eval-jobs because it doesn't actually
use anything from it.

Change-Id: Icf29938688f4fa87425ff346a3105ef56a6a6964

lix/libcmd/lix-cmd.pc.in

@@ -7,4 +7,4 @@ Description: Lix Package Manager (libcmd)
 Version: @PACKAGE_VERSION@
 Requires: lix-base lix-util lix-store
 Requires.private: lix-fetchers lix-expr lix-main @BOEHM_IF_FOUND@ libeditline lowdown ncurses
-Libs: -L${libdir} @LIBLIX_DOC_IF_STATIC@ -llixcmd
+Libs: -L${libdir} -llixcmd

lix/libcmd/meson.build

@@ -94,6 +94,5 @@ configure_file(
     'includedir' : includedir,
     'PACKAGE_VERSION' : meson.project_version(),
     'BOEHM_IF_FOUND' : boehm.found() ? 'bdw-gc' : '',
-    'LIBLIX_DOC_IF_STATIC' : is_static ? '-llix_doc' : '',
   },
 )

lix/lix-base.pc.in

@@ -7,3 +7,4 @@ Description: Lix Package Manager (base include dir)
 Version: @PACKAGE_VERSION@
 Requires: kj-async
 Cflags: -I${includedir}
+Libs: -L${libdir} -lrust_monocrate