This aligns options that do the same thing:
1) `skipSpecs` and `spec` has been deprecated in favor of `skipTests`.
2) `styleext` has been deprecated in favor of `style` since the latest is two words.
Fixes#12784
This should clean up the code a bit.
Note: at first I added the no-useless-cast rule, but after getting frustrated
with it (as it has many false positive), I decided to remove the rule but some
useless casts were removed so I let those in the PR.