feat: replace buttons in /configure-channels with select menu

Catalogger.Backend/Cache/InMemoryCache/UserCache.cs

@@ -13,7 +13,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-using System.Diagnostics.CodeAnalysis;
 using Catalogger.Backend.Extensions;
 using LazyCache;
 using Remora.Discord.API.Abstractions.Objects;