extend e2e test to cover token renewal

[clux]

What problem are you trying to solve?

Currently our e2e test only checks that cluster auth works, not whether it continues to work past reload points.
Token reloading was introduced in 0.69.0 and we did not have e2e coverage of tests verifying this causing #829.

Describe the solution you'd like

Would like to ensure that e2e tests catch issues related to in-cluster auth and token renewal.

Extend dapp to wait across renewal points and make an api call after this to ensure things still work.

If nessary, expose a sneaky way to reduce refresh time (see #797), and set it for this e2e test, so that we don't have to wait a full minute just to test this for every PR.

Describe alternatives you've considered

running a larger controller test on ci. would still not catch this particular issue.

Target crate for feature

• e2e
• kube-client