Fix senpai-irc classification for new upstream location

[supertassu]

~~The chess engine is no longer packaged in AUR (nor was it ever packaged anywhere else), so this is no longer necessary. The classification was already a bit broken due to the upstream move from git.sr.ht/~taiite/senpai to git.sr.ht/~delthas/senpai, but I think removing it entirely is a better option than fixing it.~~

The upstream repository recently moved from https://git.sr.ht/~taiite/senpai to https://git.sr.ht/~delthas/senpai.

[AMDmi3]

Let's fix it instead. Split rules should never be removed, as the name is known to be ambiguous, and the chess engine package may reappear anytime.

[supertassu]

Sure, updated.