[ ikuradon/tsunagiya ] fix(ci): drop Deno v1.x from CI matrix

deno.lock v5 format is not supported by Deno 1.x.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
https://github.com/ikuradon/tsunagiya/commit/df7605aa9530cd0b7657e3301773c0c0ad23c829