fix(docker): remove NopCloser from the executor. See #2261

[tcolgate]

This ensure that we properly close both stdout and stderr pipes after
executing docker logs.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I have written unit and/or e2e tests for my change. PRs without these are unlike to be merged.
• Optional. I've added My organization is added to the README.
• I've signed the CLA and required builds are green.

[tcolgate]

This is an attempt to resolve #2261.
I'm not sure this is actually the cause, but this seems more correct regardless.

[alexec]

I've re-triggered this CI workflow, as it maybe flakey.

[alexec]

This should probably be backported to v2.6.0.

[codecov]

Codecov Report

Merging #2345 into master will decrease coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2345      +/-   ##
==========================================
- Coverage   13.38%   13.29%   -0.09%     
==========================================
  Files          70       72       +2     
  Lines       24232    24602     +370     
==========================================
+ Hits         3244     3272      +28     
- Misses      20579    20917     +338     
- Partials      409      413       +4     

Impacted Files	Coverage Δ
workflow/validate/validate.go	74.57% <0.00%> (-0.85%)	⬇️
workflow/cron/controller.go	0.00% <0.00%> (ø)
workflow/cron/operator.go	12.92% <0.00%> (ø)
workflow/controller/operator.go	61.86% <0.00%> (+0.45%)	⬆️
workflow/controller/exec_control.go	28.04% <0.00%> (+2.43%)	⬆️

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[alexec]

Cherry-picked to `release-2.6' for v2.6.1.