⬆️ Updates Markdown to v3.8.1 [SECURITY]

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

Author: renovate[bot]

docs/requirements_frozen.txt

@@ -3,7 +3,7 @@ click-man==0.4.1
 mkdocs==1.2.3
 Pygments==2.12.0
 mkdocs-material==8.2.7
-Markdown==3.3.6
+Markdown==3.8.1
 markdown-checklist==0.4.3
 fontawesome-markdown==0.2.6
 markdown-include==0.6.0