ci: Add linter stage to workflow #426

Job	Run time
test (debos-arch)	1m 27s
test (debos-bookworm)	1m 9s
test (debos-bullseye)	58s
test (debos-trixie)	1m 32s
Check DockerHub secrets exist	1s
lint	57s
Build Docker container	8m 31s
recipes on nofakemachine	53s
debian (amd64) on nofakemachine	2m 14s
debian (arm64) on nofakemachine	3m 31s
debian (armhf) on nofakemachine	3m 0s
recipes on qemu	1m 5s
debian (amd64) on qemu	7m 39s
debian (arm64) on qemu	12m 7s
debian (armhf) on qemu	11m 54s
recipes on uml	52s
debian (amd64) on uml	5m 3s
debian (arm64) on uml	9m 50s
debian (armhf) on uml	10m 20s
arch on arch	13m 3s
partitioning on qemu	1m 35s
apertis on uml	9m 20s
partitioning on uml	58s
Run unit tests	2m 35s
allgreen	2s
Publish to GHCR	1s
Publish to DockerHub	1s
	1h 50m 38s

Provide feedback