ETag/304 conditional requests are redundant on immutable, content-addressed bundle/deployment endpoint

[sulksamino]

Bug description

The APIs for requesting a bundle (/api/v1/clients/{clientId}/bundles/{digest}) or single deployment (/api/v1/clients/{clientId}/deployments/{deploymentId}/{digest}) call for the If-None-Match header to allow caching. While I understand the principal mechanism behind the If-None-Match header and 304 response it feels unnecessary and confusing for these two cases.
A context aware client knows that these resources are addressed by their digest which means they can not change. So I see no reason why a client would send the request if it already has the response cached.

The response on /api/v1/clients/{clientId}/deployments/{deploymentId}/{digest} also has no 304 response defined.

Proposed fix

Drop the If-None-Headers for both paths and the 304 response for /api/v1/clients/{clientId}/bundles/{digest}

Anything else (optional)

https://github.com/margo/specification/blob/pre-draft/system-design/specification/margo-management-interface/workload-management-api-1.0.0.yaml