* Just set LED_BUILTIN universally to -1, as we don't use it.
* LUD_BUILTIN workarounds
* Squash the LED_BUILTINs that sneaked in
* Don't kill valid pin derfine
Remove lib_deps section for all PlatformIO envs which are unneeded (only references the `extends` lib_deps, thus pointless)
This makes the configs more concise and make future PIO variants/ libdeps audits easier.