[Feat]: CI for 1.0 and 0.3 TCKs against cohosted 1.0 and 0.3 servers

[kabir]

This is a bit complicated since the SUT for 1.0 now lives in a2a-tck.

But we should ensure that if we have the TCK server with both 1.0 and 0.3 enabled that both the 1.0 and 0.3 TCKs pass

[jmesnil]

What we could do is put back the a2a-java SUT in the tck module here.
It would be a copy/paste of https://github.com/a2aproject/a2a-tck/tree/1.0-dev/sut/a2a-java and would serve both 1.0 and 0.3.

Then we could run the 2 tck against it.
It would be up to the TCK maintainer (aka me) to send PRs to updated the AgentExecutor if the tests requires additional scenarios from the AgentExecutor.

@kabir wdyt?

[kabir]

@jmesnil Yeah I think that sounds reasonable (as an interim solution at least).

Note I think we should also have 1.0 TCK against a 1.0 only server, as well as 0.3 TCK against a 0.3 only server.