Fix RTD docs builds

.readthedocs.yaml

@@ -0,0 +1,22 @@
+---
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the version of Python in the build environment.
+build:
+  os: "ubuntu-22.04"
+  tools:
+    python: "3.10"
+
+mkdocs:
+  configuration: "mkdocs.yml"
+  fail_on_warning: false
+
+# Use our docs/requirements.txt during installation.
+python:
+  install:
+    - requirements: "docs/requirements.txt"

docs/requirements.txt

@@ -1,2 +1,2 @@
-mkdocs==1.3.0
+mkdocs==1.6.0
 markdown-include==0.6.0