remove deprecated items.

[kivikakk]

It's been a minute.

[codspeed-hq]

Merging this PR will not alter performance

✅ 1 untouched benchmark

---

_{Comparing push-orlpwlpryykn (0623dd3) with main (087b0ce)}

[github-actions]

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
./bench.sh ./comrak-0d08a69	103.1 ± 1.9	100.3	107.1	1.95 ± 0.05
./bench.sh ./comrak-main	102.7 ± 2.0	100.6	110.2	1.95 ± 0.06
./bench.sh ./pulldown-cmark	52.8 ± 1.1	51.6	59.6	1.00
./bench.sh ./cmark-gfm	81.0 ± 6.6	74.6	94.3	1.53 ± 0.13
./bench.sh ./markdown-it	213.9 ± 1.4	211.4	216.5	4.05 ± 0.09

Run on Sun Jul 12 00:30:25 UTC 2026