build: eliminate kill of already stopped containers

[efahl]

Some error paths result in the container.kill being called twice. This results in an erroneous error report to the user, with the podman error superseding the actual build error in the message output:

409 Client Error: Conflict (can only kill running containers...

Fix it by removing the extra calls.

[efahl]

@aparcar I found this one by scanning my log output from https://github.com/openwrt/asu/pull/1522 running on my local server. It would be nice to get 1522 in, too, so I can see more of what's going on with the 3-400 errors/day on the production server...

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 92.40%. Comparing base (5e65dec) to head (042c737). :warning: Report is 315 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1529       +/-   ##
===========================================
+ Coverage   80.75%   92.40%   +11.64%     
===========================================
  Files          15       15               
  Lines         977     1382      +405     
===========================================
+ Hits          789     1277      +488     
+ Misses        188      105       -83     

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[efahl]

See https://github.com/openwrt/asu/issues/1530 as an example...

[efahl]

@aparcar Can we get this bug fix in, too? It's causing me headaches with trying to figure out root cause of issues due to it masking real errors.

[efahl]

Thanks!

[aparcar]

Deployed