⬆️ Configure dependabot to ignore Python version updates

Python version should be constrained by the anaconda distribution version
specified in environment.yml, not updated independently by dependabot.

Author: mmcky

.github/dependabot.yml

@@ -14,5 +14,12 @@ updates:
       interval: weekly
   - package-ecosystem: "conda"
     directory: "/"
+    commit-message:
+      prefix: ⬆️
     schedule:
-      interval: "weekly"
+      interval: "weekly"
+    ignore:
+      - dependency-name: "jupyter-book"
+        versions: [">=2.0"]
+      - dependency-name: "python"
+        # Python version should be constrained by the anaconda distribution version