Get rid of Dehydra scripts

[Itms]

We currently have one Dehydra script under ps/trunk/build/dehydra which can check our printf-like functions. It is supposed to complement GCC's own analysis.

However, Dehydra is completely left abandoned (​https://developer.mozilla.org/en-US/docs/Archive/Mozilla/Dehydra) and we don't really use it anyways.

We should get rid of this and include the custom script in the static code analysis we are setting up. Basically, are cppcheck and clang's scan-build both unable to detect the issue? If yes, try to extend somehow one of them to detect it. Else just drop the dehydra code.

[Stan]

Also one shouldn't forget to delete it from the wiki wiki:CodeQuality

Somehow related to the static analysis #3958, #4447

[Vladislav Belov]

In 25523:

Removes dehydra build scripts following rPrP25521. Fixes #4446

Refs rP7175.