remove old node / electron version

[julianhille]

for a v5 and to be able to still build we need to remove old versoins:

• node 15 and 16 needs to be removed both are eol
• electron 15 to 19 (those eols are older than 2 years)

as i know there is plenty of old stuff out there i try to be as unobtrusive as possible.

[julianhille]

regarding the sheer amount of electron versions coming out will end up in a huge amount of prebuilts.

i need to consider to support less electron versions