boot: detect error message in final phase

This commit adds error message detection in the final bootloader-commands action.

Closes: #308
15 jobs for detect-final-error in 12 minutes and 1 second (queued for 4 seconds)
Status Job ID Name Coverage
  Test
passed #59774
amd64
dispatcher-debian-10

00:03:03

passed #59772
amd64
dispatcher-debian-9

00:03:20

passed #59775
amd64
server-debian-10

00:02:34

passed #59773
amd64
server-debian-9

00:03:00

 
  Analyze
passed #59777
amd64
black

00:00:30

passed #59778
amd64
code_quality

00:00:23

passed #59779
amd64
dockerfiles

00:00:21

passed #59780
amd64
job-schema

00:00:26

passed #59781
amd64
pylint

00:02:45

passed #59776
amd64-dind allowed to fail
sast

00:01:54

 
  Build
passed #59784
amd64
amd64/pkg-debian-10

00:01:16

passed #59783
amd64
amd64/pkg-debian-9

00:01:41

passed #59782
amd64
doc

00:01:12

 
  Docker
passed #59785
amd64-dind
amd64/lava-dispatcher

00:03:51

passed #59786
amd64-dind
amd64/lava-server

00:04:11