Refactor image builds

[CoryManson]

• Add Lakka 5.0
• Add Batocera 39
• Break buildroot builds out into their own shell scripts
• Decrease buildroot image sizes
• Switch to gzip from xz
• Only upload images larger than 2GB to storage account to reduce cost
• Finally settle on a naming convention for images
• Remove unused packer builds
• Improve workflow
  • Add default release body text
  • Allow manual execution of workflow
  • Write notice on workflow output when image larger than 2GB is found

[othermod]

Your latest Zero 2 images for Kali and Batocera definitely aren't behaving. I'm getting immediate poweroff initially on the images, which I solved by moving to the separate files pi0.txt and cm4.txt. They definitely aren't getting parsed correctly. Maybe it's a size limit or something. Here's my method:

This one applies to CM4 only. I do this because the Pi4 needs its own config, but if I do [pi4] then the cm4 also loads for config the pi4. I'll also have to specify the pi4 board-type when i make an image for it. [board-type=0x14] include cm4.txt

this will load for the Pi0 and the Pi02 [pi0] include pi0.txt

I pushed these separate config files to my repository and modified the config.txt for each os. I think there only needs to be a single pi0.txt and cm4.txt for each os to reference, since they all need the exact same info.

I still can't get a successful bootup on either image, but Kali they at least tries once the config.txt is modified. Haven't tried all of the other images yet.

[CoryManson]

awesome. Because I don't have a Zero 2 to test with, any zero builds are just a shot in the dark and require testing / changes so them not working is fully expected.

I'll add zero 2 images for all the OS to this PR today and we'll dial in the configs over the next little while before publishing. I'll try and get AP to help.

[CoryManson]

This is ready for review. All images have been tested working on Pi Zero 2W & CM4 with the only exception being Retropie on the Zero 2W.

Kali was been removed which also allowed for removal of external storage requirements.