Update dependency mkdocs-material to v9.6.18

Author: slack-oss-bot

.github/workflows/mkdocs-requirements.txt

@@ -7,7 +7,7 @@ Markdown==3.7
 MarkupSafe==3.0.2
 mkdocs==1.6.1
 mkdocs-macros-plugin==1.3.7
-mkdocs-material==9.6.12
+mkdocs-material==9.6.18
 mkdocs-material-extensions==1.3.1
 Pygments==2.18.0
 pymdown-extensions==10.12