server: allow to like own gallery posts

Since you are also allowed to react to your own notes, it seems sensible
that you should be allowed to like your own gallery posts.

Analogous to commit 4c5aa9e538.

Changelog: Changed

packages/backend/src/server/api/endpoints/gallery/posts/like.ts

@@ -17,12 +17,6 @@ export const meta = {
 			id: '56c06af3-1287-442f-9701-c93f7c4a62ff',
 		},
 
-		yourPost: {
-			message: 'You cannot like your post.',
-			code: 'YOUR_POST',
-			id: 'f78f1511-5ebc-4478-a888-1198d752da68',
-		},
-
 		alreadyLiked: {
 			message: 'The post has already been liked.',
 			code: 'ALREADY_LIKED',
@@ -46,10 +40,6 @@ export default define(meta, paramDef, async (ps, user) => {
 		throw new ApiError(meta.errors.noSuchPost);
 	}
 
-	if (post.userId === user.id) {
-		throw new ApiError(meta.errors.yourPost);
-	}
-
 	// if already liked
 	const exist = await GalleryLikes.findOneBy({
 		postId: post.id,