Stop workaround xapian-core.pc

`xapian-core.pc` is now correct stop workaround it adding extra
link args.
The workaround is broken with meson 0.44.0 and static compilation.

However, libmicrohttpd is using `librt` if present but doesn't declare
it in its `libmicrohttpd.pc` file so we must add it manually if we found
it.

meson.build

@@ -15,22 +15,14 @@ kiwixlib_dep = dependency('kiwix', version:'>=1.0.0', static:static_linkage)
 microhttpd_dep = dependency('libmicrohttpd', static:static_linkage)
 z_dep = dependency('zlib', static:static_linkage)
 
-# This is a temporary workaround until xapian fix it's xapian-core.pc
-# For a correct dependency checking we should test if uuid is really installed
-# but for a workaround, we assume that in xapian is installed, uuid also.
-if meson.is_cross_build() and host_machine.system() == 'windows'
-    # xapian doesn't use uuid on windows.
-    uuid_dep = declare_dependency()
-else
-    xapian_dep = dependency('xapian-core', required : false)
-    if xapian_dep.found()
-        uuid_dep = declare_dependency(link_args:['-luuid', '-lrt'])
-    else
-        uuid_dep = declare_dependency()
-    endif
-endif
+all_deps = [thread_dep, kiwixlib_dep, microhttpd_dep, z_dep]
 
-all_deps = [thread_dep, kiwixlib_dep, microhttpd_dep, z_dep, uuid_dep]
+if static_linkage
+  librt = compiler.find_library('rt', required:false)
+  if librt.found()
+    all_deps += librt
+  endif
+endif
 
 #subdir('include')
 subdir('static')