chore: use testify instead of testing in tests/e2e

[mmorel-35]

Description

This uses testify instead of testing for t.Fatal or t.Error calls in tests/e2e package

Related to #18972

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: mmorel-35
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.78%. Comparing base (f07e2ae) to head (072905f).

Additional details and impacted files

see 28 files with indirect coverage changes

@@           Coverage Diff           @@
##             main   #19615   +/-   ##
=======================================
  Coverage   68.77%   68.78%           
=======================================
  Files         421      421           
  Lines       35897    35897           
=======================================
+ Hits        24689    24692    +3     
+ Misses       9786     9772   -14     
- Partials     1422     1433   +11     

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