Allow build.commands without build.tools (#10281)
* Adjust tests
* Update validation to allow build.commands without build.tools
* Remove comments, adds a negative test about re: "`build.jobs` can't be used without using `build.os`"
* Rename BuildWithTools => BuildWithOs
* Not legacy, still supported!
* Make test case command not confuse, it should make sense
* Adds a note to remember to create the folders before adding content
* Improve a docs sentence
* Use $READTHEDOCS_OUTPUT in examples
* Update docs/user/build-customization.rst
Co-authored-by: Manuel Kaufmann <humitos@gmail.com>
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Co-authored-by: Manuel Kaufmann <humitos@gmail.com>
