chore(deps): update dependency markdownlint-cli2 to v0.21.0 (#2631)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

mise.toml

@@ -1,6 +1,6 @@
 [tools]
 lychee = "0.22.0"
-markdownlint-cli2 = "0.20.0"
+markdownlint-cli2 = "0.21.0"
 
 [settings]
 # Only install tools explicitly defined in the [tools] section above