[release-1.20] Bump cert-manager to v1.19.0

[mboersma]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

Manual cherry-pick of #5910.

Updates cert-manager to the current release v1.19.0 to sync with CAPI.

Which issue(s) this PR fixes:

N/A, but see #5711 for prior art.

Special notes for your reviewer:

TODOs:

• squashed commits
• includes documentation
• adds unit tests
• cherry-pick candidate

Release note:

NONE

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 52.81%. Comparing base (f96822a) to head (e06008e).
⚠️ Report is 5 commits behind head on release-1.20.

Additional details and impacted files

@@              Coverage Diff              @@
##           release-1.20    #5911   +/-   ##
=============================================
  Coverage         52.80%   52.81%           
=============================================
  Files               279      279           
  Lines             29602    29602           
=============================================
+ Hits              15632    15634    +2     
+ Misses            13156    13154    -2     
  Partials            814      814           

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[nojnhuh]

/lgtm
/approve

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 05457199f60867ca2a013fa3c434f975c21a3f87

[k8s-ci-robot]

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