Fix examples of number_to_percentage

[ci skip]
Use the canonical router on the CHANGELOG entry

Thanks @egilburg

[ci skip]
Revert "Fix SyntaxError in guides sample code"

This reverts commit f573df32d43c413a5098721ba6151ff190c23c6c.

The original idea of this documentation was to showcase the feature
where you can remove some only queries attributes with a single
key-value pair.
remove duplication in test
Merge pull request #11491 from erichkist/ek-revert-unscope-patch

Revert "Fix SyntaxError in guides sample code"
Merge pull request #11492 from maratvmk/concern_test

remove duplication in concern_test