Small changes to the text and CMake code for the fourth step of the
tutorial:
* Remove parameter from endfunction call
* Standardize on "binary directory" for test location
* Add additional information about a Release build.
Issue: #22663
Extend the change from commit 9e5bbb69ea (Tutorial: Add captions for
code blocks, 2021-06-11) to also add a Sphinx named target to code
blocks. Name each target after the change the code block makes.
