Enable larger results without a sidecar on every TaskRun

[arewm]

Feature request

We are trying to use Tekton Chains in order to generate provenance attestations for artifacts produced during a PipelineRun. Use of type hinting means that we need to output the image URI in results so that Chains can find it. While this approach works fine when there are a small number of artifacts produced in a TaskRun, it quickly becomes insufficient as the length of a digest-pinned OCI reference, for example, will quickly consume the available space for results, especially if a task has multiple steps.

One of the main recourses that we have considered is to start using sidecar containers to increase the space available for results, but this will result in a larger consumption for every TaskRun whether it needs additional result space or not. Since I know which tasks are likely to overflow the space available for results, I would like to be able to selectively increase the result size limit to be a more responsible cluster tenant.

Use case

• As a Task developer, I want to selectively increase the size available for my results.
• As a Task developer, I want to be able to easily create a new task that will result in many artifacts being signed by Chains.