Delete the remainder of groups (#9357)

* Delete the remainder of groups

Fixes https://github.com/vector-im/element-web/issues/22770
Continues https://github.com/matrix-org/matrix-react-sdk/pull/8027

* Don't need the strings either

src/utils/permalinks/MatrixSchemePermalinkConstructor.ts

@@ -51,10 +51,6 @@ export default class MatrixSchemePermalinkConstructor extends PermalinkConstruct
         return `matrix:${this.encodeEntity(userId)}`;
     }
 
-    forGroup(groupId: string): string {
-        throw new Error("Deliberately not implemented");
-    }
-
     forEntity(entityId: string): string {
         return `matrix:${this.encodeEntity(entityId)}`;
     }