Enable TLS for OIDC e2e tests

[mgencur]

The E2E tests under test/auth verify OIDC authentication but don't enable TLS.
The OIDC features is mostly useful when TLS is enabled for communication between components.

TLS can be enabled for reconciler-test through WithTLS option:

ctx, env := global.Environment(
  ..
  eventshub.WithTLS(t)
  ...
)

The tests will need to be modified to properly start EventsHub receiver/sender with enforced TLS and individual resources which deliver events will have to specify CACerts for Destination:

d := service.AsDestinationRef(sink)
d.CACerts = eventshub.GetCaCerts(ctx)

[Cali0707]

/triage accepted

[Leo6Leo]

/assign
This Issue will be ready to work on after #7320 is completed

[creydr]

@Leo6Leo thanks for taking this.
You can also split this into multiple PRs (e.g. my migrating the tests for apiserversource, broker, channel, containersource, ... separately), so you don't have to wait for #7320