spa: declare a dependency for the dbus lib

When running meson test without a preceding ninja build, we end up with
missing libraries. This somehow happened to work until recently but now
it triggers an issue with libspa-dbus.so not being available during the
valgrind test run, causing a test case to fail.

spa/plugins/support/meson.build

@@ -43,6 +43,9 @@ if dbus_dep.found()
     dependencies : [dbus_dep, ],
     install : true,
     install_dir : spa_plugindir / 'support')
+  spa_dbus_dep = declare_dependency(link_with: spa_dbus_lib)
+else
+  spa_dbus_dep = declare_dependency()
 endif
 
 

test/meson.build

@@ -73,6 +73,7 @@ test('test context',
                'test-context.c',
                'test-config.c',
                include_directories: pwtest_inc,
+               dependencies: [spa_support_dep, spa_dbus_dep],
                link_with: [pwtest_lib,
                             pipewire_module_protocol_native,
                             pipewire_module_client_node,