Add conditional dependency for libkeyutils

This modification enables better control over the inclusion of libkeyutils
based on the configuration, enhancing the flexibility of the build system.

Signed-off-by: Max Fritz <antischmock@googlemail.com>
Message-Id: <168471463402.18155.3575359027429939965-1@git.sr.ht>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[thuth: Remove the "kwargs: static_kwargs" part - it's not necessary anymore]
Signed-off-by: Thomas Huth <thuth@redhat.com>

meson.build

@@ -1781,8 +1781,10 @@ if gnutls.found()
   tasn1 = dependency('libtasn1',
                      method: 'pkg-config')
 endif
-keyutils = dependency('libkeyutils', required: false,
-                      method: 'pkg-config')
+keyutils = not_found
+if get_option('keyring').enabled()
+  keyutils = dependency('libkeyutils', required: false, method: 'pkg-config')
+endif
 
 has_gettid = cc.has_function('gettid')