formatting 1/n: pl_examples

[Borda]

What does this PR do?

apply YAPF on our examples as showcase how it can look like 🐰

Before submitting

• Was this discussed/approved via a GitHub issue? (not for typos and docs)
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• Did you write any new necessary tests? (not for typos and docs)
• Did you verify new and existing tests pass locally with your changes?
• Did you update the CHANGELOG? (not for typos, docs, test updates, or internal minor changes/refactorings)

PR review

Anyone in the community is free to review the PR once the tests have passed.
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Did you have fun?

Make sure you had fun coding 🙃

[codecov]

Codecov Report

Merging #5709 (b6580d7) into release/1.2-dev (a17c941) will decrease coverage by 0%.
The diff coverage is n/a.

@@               Coverage Diff                @@
##           release/1.2-dev   #5709    +/-   ##
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- Coverage               89%     89%    -0%     
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  Files                  168     168            
  Lines                12423   12267   -156     
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- Hits                 11103   10924   -179     
- Misses                1320    1343    +23