chore(deps-dev): bump mkdocs-material from 9.1.19 to 9.1.21 (#2894)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

poetry.lock

@@ -68,7 +68,7 @@ mypy-boto3-s3 = "^1.28.8"
 mypy-boto3-xray = "^1.28.15"
 types-requests = "^2.31.0"
 typing-extensions = "^4.6.2"
-mkdocs-material = "^9.1.19"
+mkdocs-material = "^9.1.21"
 filelock = "^3.12.2"
 checksumdir = "^1.2.0"
 mypy-boto3-appconfigdata = "^1.28.15"