[bitnami/external-dns] Add support for --txt-new-format-only

[MaxAnderson95]

Description of the change

This PR adds support for the new --txt-new-format-only flag introduced in External DNS v0.16.0 PR #4946

Benefits

This allows operators using the TXT registry for storing ownership records, to only need to store a single record. Since the new format was introduced, each A/CNAME record creates two separate ownership records. One in the old format, and one in the new.

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

[jotamartos]

Thank you for your contribution.

[jotamartos]

Sorry for the noise, but can you make the suggested change so all parameters are shown together in the readme?

[MaxAnderson95]

Sorry for the noise, but can you make the suggested change so all parameters are shown together in the readme?

@jotamartos I've implemented your suggestion. This is ready for your review!

[MaxAnderson95]

Bump

[jotamartos]

Accepting after resolving conflicts

[MaxAnderson95]

Thanks @jotamartos, was there anything else that needed to be done or can this be merged and closed?

[jotamartos]

That's all @MaxAnderson95. I accepted the PR but the automation added a new commit after applying the changes so I needed to accept it again. It's now merged. Thanks for your contribution.

[rouke-broersma]

@jotamartos note that this flag does not remove existing records, so when users enable this option they could be left with thousands of stale unmanaged TXT records. You may wish to add a warning to the docs about this.