Update version to 0.15.1.beta2

Merge pull request #4244 from MoonModules/framerate_ac015

Improved framerate control code - strip.show(), strip.service()

use npm ci

update changelog for 2412100

Merge branch '0_15_0' of https://github.com/Aircoookie/WLED into 0_15_0

Merge pull request #4231 from Aircoookie/b7

WLED 0.15.0-b7 release

WLED 0.15.0-b6 release (#4180)

* modified Improv chip & version handling
* Update build and changelog

WLED 0.15.0-b5 release

- Audioreactive usermod always included

Merge branch 'main' into 0_15

Build bump, changelog update