fix: adapt NcButtons to nextcloud-vue 9

Signed-off-by: grnd-alt <github@belakkaf.net>

src/components/navigation/AppNavigationBoard.vue

@@ -129,17 +129,17 @@
 				:placeholder="t('deck', 'Board name')"
 				type="text"
 				required />
-			<NcButton type="tertiary"
+			<NcButton variant="tertiary"
 				:disabled="loading"
-				native-type="submit"
+				type="submit"
 				:title="t('deck', 'Cancel edit')"
 				@click.stop.prevent="cancelEdit">
 				<template #icon>
 					<CloseIcon :size="20" />
 				</template>
 			</NcButton>
-			<NcButton type="tertiary"
-				native-type="submit"
+			<NcButton variant="tertiary"
+				type="submit"
 				:disabled="loading"
 				:title="t('deck', 'Save board')">
 				<template #icon>