fix: use the correct values naming within hydra-maester for consistency

[adamstrawson]

The use of annotation within hydra-maester is inconsistent with the other Ory Helm Charts, as well as it's own documentation.

The hydra-maester documentation specified deployment.annotations already, and the other charts use the same format.

BREAKING CHANGES: This patch changes the behavior of configuration item `annotation`. To keep the existing
behavior please do `deployment.annotation`.

Checklist

• [X] I have read the contributing guidelines and signed the CLA.
• [ ] I have referenced an issue containing the design document if my change introduces a new feature.
• [X] I have read the security policy.
• [X] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got green light (please contact security@ory.sh) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [X] I have added necessary documentation within the code base (if appropriate).

[Demonsthere]

Hi there! You are correct, the values is not consistent with the rest of the ory ecosystem :/ However your method introduces a breaking change, instead I would suggest the usage of ternary operator:

{{- $annotations := ternary .Values.deployment.annotations .Values.deployment.annotation (not (empty .Values.deployment.annotations )) -}}

this format would support both and not be a breaking change :) Please add in your PR an empty object as the default value for annotations, and some test annotations to the test overrides in the hack folder :)