Replace the Knative API dependencies with duck types

[michalvavrik]

• I wasn't sure about this table, https://camel.apache.org/camel-k/next/concepts/dependencies.html, KEDA and Strimzi doesn't have something similar, so I used 1.20.1 which is what we test and is API of a sort, but isn't called "Knative API".
• AI disclosure: I used Claude Opus during development, to help me iterate and find bugs and run tests in a fork CI, then refactored it and fixed few things manually before opening this PR.

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• closes: Consider moving Knative API to duck types #6354

[squakez]

Thanks a lot for the work. A few comments about the changes:

• we can remove the mention to the knative serving version and the script that regen it
• I don't see a strong reason to test the duck types, they are even skipped from coverage
• I am not sure we need the entire API set. We should probably only identify those object that we use along the code and the related fields used.
• I realize we need to restrict the work on serving API only. Eventing is deprecated on our side (just added a note to the issue)
• Nice to see additional tests adding coverage beside the API ones, we can keep them

Overall it seems complete, we can make some cleaning to reduce the size of the API to the real code usage and the duck types unit tests. We can even keep eventing now that the work is done.

[github-actions]

✔️ Unit test coverage report - coverage increased from 63.8% to 64.1% (+0.3%)

[squakez]

I think we can merge this one and work on follow up issues to polish the pending points identified during the review, or do you prefer tackling them before?

[michalvavrik]

I think we can merge this one and work on follow up issues to polish the pending points identified during the review, or do you prefer tackling them before?

I prepared changes you asked for yesterday, but I need to finish something else now and go over it again now that I am not tired. I'll push it as a separate commit later today and you will be able to decide if you want this new version or we can drop it and merge the original commit (or I'll address more comments of course).