Add Dependabot group for Redux

There are often dependencies between core Redux and packages building
on Redux like Redux Toolkit, React Redux, Redux Persist.

Group them to make them move in parallel.

.github/dependabot.yml

@@ -27,6 +27,13 @@ updates:
           - "@graphql-typed-document-node/core"
           - "replace-in-file"
           - "typescript-graphql-typed-files-modules"
+      redux:
+        patterns:
+          - "@reduxjs/toolkit"
+          - "@types/react-redux"
+          - "react-redux"
+          - "redux"
+          - "redux-persist"
       storybook:
         patterns:
           - "@storybook/*"