Deprecation of tanka deployment tooling

[barroco]

As proposed in #874 as part of the work of streamlining the DSS operations and simplifying users on-boarding, InterUSS contributors have been discussing replacing the tanka deployment approach by helm.
The migration to yugabyte seems the right time to complete this migration and not include support for this approach. This would reduce the amount of effort to maintain both approaches and simplify documentation.

The community is invited to provide feedback before July 10, 2025.

[callumdmay]

Does helm support the same merge functionality that Tanka does? We override a few of the defaults that InterUSS provides, and Tanka makes this really easy.

[barroco]

Does helm support the same merge functionality that Tanka does? We override a few of the defaults that InterUSS provides, and Tanka makes this really easy.

Helm is not as flexible as jsonnet since it is based on jinja2 templates. The mechanism to override defaults is different. Indeed, it is performed using values, which are explicit inputs to the helm charts.

Regarding the overrides, would it be possible to share which one are important to you so we can assess how we can address this with Helm ?