fix(SupportProject): migrate NcButton type to variant prop

The 'type' prop for color variants was removed in @nextcloud/vue
v9.0.0 in favour of the 'variant' prop.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

src/views/Settings/SupportProject.vue

@@ -11,7 +11,7 @@
 				{{ t('libresign', 'LibreSign is developed with ❤️ by LibreCode coop. Your support helps us maintain and improve this free and open-source project.') }}
 			</p>
 			<div class="support-buttons">
-				<NcButton type="primary"
+				<NcButton variant="primary"
 					href="https://github.com/sponsors/libresign"
 					target="_blank"
 					rel="noopener noreferrer">