Bump mkdocs from 1.1.2 to 1.2.3 in /requirements (#1156)

dependabot[bot] · web-flow · commit f2c50d49d1e2 · 2022-01-03T13:43:05.000+01:00
diff --git a/requirements/requirements_doc.txt b/requirements/requirements_doc.txt
@@ -1,2 +1,2 @@
-mkdocs==1.1.2
+mkdocs==1.2.3
 mkdocs-material==8.1.3
