Skip retrieving listeners for pods that have a deletionTimestamp to avoid deadlock waiting for secret operator pvcs when the listeners have already been garbage collected

[soenkeliebau]

Description

fixes #720

Definition of Done Checklist

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Author

• Changes are OpenShift compatible
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
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• Release note snippet added
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• Add type/experimental label & add to the experimental features tracker