[release-1.19] Bump cert-manager to v1.18.1

[mboersma]

This is a manual cherry-pick of #5711

NONE

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.57%. Comparing base (bf7243c) to head (e79aa39).
Report is 9 commits behind head on release-1.19.

Additional details and impacted files

@@              Coverage Diff              @@
##           release-1.19    #5723   +/-   ##
=============================================
  Coverage         52.57%   52.57%           
=============================================
  Files               272      272           
  Lines             29474    29474           
=============================================
  Hits              15495    15495           
  Misses            13177    13177           
  Partials            802      802           

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[mboersma]

/retest

[alimaazamat]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: ef80b0cf99b90cfb1cb22f11fdb2dab9df5c5c3b

[nojnhuh]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nojnhuh

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