Improve test stability

[johscheuer]

Description

Make sure the test setup is correct and the tests are stable.

Type of change

Please select one of the options below.

• Bug fix (non-breaking change which fixes an issue)

Discussion

Testing

CI will run the e2e tests.

Documentation

N/A

Follow-up

[foundationdb-ci]

Result of fdb-kubernetes-operator-pr on Linux CentOS 7

• Commit ID: 17ae82d
• Duration 3:22:00
• Result: ❌ FAILED
• Error: Error while executing command: if $fail_test; then exit 1; fi. Reason: exit status 1
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[johscheuer]

Summarizing 1 Failure:
  [FAIL] Operator Upgrades upgrading a cluster with a random Pod deleted during rolling bounce phase [It] Upgrade from 7.1.37 to 7.3.15 with pods deleted during rolling bounce [e2e, pr]
  /codebuild/output/src2183488254/src/github.com/FoundationDB/fdb-kubernetes-operator/e2e/test_operator_upgrades/operator_upgrades_test.go:160

with the failure:

Operator Upgrades upgrading a cluster with a random Pod deleted during rolling bounce phase [It] Upgrade from 7.1.37 to 7.3.15 with pods deleted during rolling bounce [e2e, pr]
/codebuild/output/src2183488254/src/github.com/FoundationDB/fdb-kubernetes-operator/e2e/fixtures/upgrade_test_configuration.go:105

  [FAILED] Unexpected error:
      <*errors.errorString | 0xc00032bb10>: 
      timed out waiting for the condition
      {
          s: "timed out waiting for the condition",
      }
  occurred
  In [It] at: /codebuild/output/src2183488254/src/github.com/FoundationDB/fdb-kubernetes-operator/e2e/test_operator_upgrades/operator_upgrades_test.go:160 @ 10/06/23 07:36:43.248
------------------------------

This is a different test failure, that will be investigated in a different PR.