chore: introduce unit test for non-blocking lifecycle operator mode

[Jay179-sudo]

Description

Added a unit test for the non-blocking lifecycle operator mode.

I used the manifest provided in the docs as the template for the unit test.

Since the non-blocking mode does not introduce any errors in the controller, we can write a unit test with a mock handler that does not return any errors when using the manifest provided in the docs.
Partially Fixes # (#3121)

How to test

Please describe how to run the tests that you ran to verify your changes.
Provide instructions so we can reproduce.
Please also provide information about any automatic tests that you added.

I use the run test option in VSCode to verify that my tests works.

• Manual Test A
• Unit Test B
• Integration Test C

Checklist

• My PR fulfills the Definition of Done of the corresponding issue and not more (or parts if the issue is separated
  into multiple PRs)
• I used descriptive commit messages to help reviewers understand my thought process
• I signed off all my commits according to the Developer Certificate of Origin (DCO)
  see Contribution Guide
• My PR title is formatted according to the semantic PR conventions described in
  the Contribution Guide
• My code follows the style guidelines of this project (golangci-lint passes, YAMLLint passes)
• I regenerated the auto-generated docs for Helm and the CRD documentation (if applicable)
• I have performed a self-review of my code
• I have made corresponding changes to the documentation (if needed)
• My changes result in all-green PR checks (first-time contributors need to ask a maintainer to approve their test runs)
• New and existing unit and integration tests pass locally with my changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.51%. Comparing base (b45e2f3) to head (9b0abb5).
Report is 152 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3581      +/-   ##
==========================================
+ Coverage   85.28%   85.51%   +0.22%     
==========================================
  Files         167      167              
  Lines        7414     7414              
==========================================
+ Hits         6323     6340      +17     
+ Misses        801      789      -12     
+ Partials      290      285       -5     

see 5 files with indirect coverage changes

Flag	Coverage Δ
certificate-operator	69.23% <ø> (ø)
component-tests	58.77% <ø> (+0.97%)	⬆️
lifecycle-operator	84.69% <ø> (+1.26%)	⬆️
metrics-operator	88.32% <ø> (ø)
scheduler	34.90% <ø> (ø)

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[odubajDT]

Thank you for your contribution!