v6.15.0

What's Changed

• [ppxyn1] WEEK 15 solutions by @ppxyn1 in #2337
• [doh6077] WEEK 15 solutions by @doh6077 in #2338
• [DaleSeo] WEEK 15 solutions by @DaleSeo in #2340
• [radiantchoi] WEEK 15 Solutions by @radiantchoi in #2342
• [juhui-jeong] WEEK 15 solutions by @juhui-jeong in #2343
• [ys-han00] WEEK 15 solutions by @ys-han00 in #2344
• [rivkode] WEEK 15 solutions by @rivkode in #2345
• [8804who] WEEK 15 solutions by @8804who in #2346
• Sponsorkit 변경 + Testimony 추가 by @DaleSeo in #2347

Full Changelog: v6.14.0...v6.15.0