Drop flashing scripts

These were split out to a separate repo

Closes: #40
4 jobs for drop-librem5-flash-image in 3 minutes and 13 seconds
Status Job ID Name Coverage
  Package
passed #361630
librem5
package-pureos-byzantium

00:01:06

passed #361631
librem5:arm64
package-pureos-byzantium:arm64

00:03:03

 
  Test Package
passed #361632
librem5
autopkgtest-pureos-byzantium-package

00:00:45

passed #361633
librem5
lintian-pureos-byzantium-package

00:00:40