Do not enable the cri check when running on a docker setup

[L3n41c]

What does this PR do?

Make a clear distinction between the docker and the CRI setup so that only one of docker or cri check is scheduled by the agent.

Motivation

Implement the same logic as the one implemented in the Helm chart with helm/charts#21476.

Additional Notes

[codecov-commenter]

Codecov Report

Merging #51 into master will increase coverage by 3.01%.
The diff coverage is 72.34%.

@@            Coverage Diff             @@
##           master      #51      +/-   ##
==========================================
+ Coverage   57.25%   60.27%   +3.01%     
==========================================
  Files          31       31              
  Lines        4216     4579     +363     
==========================================
+ Hits         2414     2760     +346     
- Misses       1620     1622       +2     
- Partials      182      197      +15     

Flag	Coverage Δ
#unittests	60.27% <72.34%> (+3.01%)	⬆️

Impacted Files	Coverage Δ
...controller/datadogagent/datadogagent_controller.go	26.11% <0.00%> (-0.34%)	⬇️
pkg/controller/datadogagent/utils.go	83.21% <75.55%> (-0.34%)	⬇️
pkg/controller/datadogagent/clusteragent.go	80.12% <0.00%> (+6.64%)	⬆️
pkg/controller/datadogagent/service.go	91.23% <0.00%> (+7.64%)	⬆️

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