Incompatibility with FastLED 3.9+

[dmadison]

The FastLED library no longer follows semantic versioning and has broken compatibility with this library. You must use FastLED version 3.7.7 or earlier in order to use this library.

This problem has been reported to the FastLED maintainers (FastLED/FastLED#1789).

[slyalfa]

I did get 3.7.8 to work with a SAMD51 but any 3.9.xx version is a no go.

[dmadison]

Version 3.7.8 compiles for me as well on AVR, although 3.7.8 is currently tagged incorrectly (FastLED/FastLED#1790) so it may not be accessible depending on how users install the library. 😟