chore(deps): update dependency mkdocs to >=1.6,<1.7

Author: renovate[bot]

setup.py

@@ -14,7 +14,7 @@
 
 docs_requires = [
     "mkautodoc",
-    "mkdocs>=1.4,<1.5",
+    "mkdocs>=1.6,<1.7",
     "portray",
     "mkdocs-material-extensions>=1.0.3",
     "pygments>=2.15,<2.16",