[Feature Request]: Add E2E test to verify prometheus metrics are exposed correctly

### Implementation ideas

In would be nice to be able to have an E2E test run on CI that verified metrics are being exposed correctly.

We could use tastora to deploy all the components and wire them up for monitoring.

I imagine this looking like a test that builds an image on a PR, uses a struct with an embedded `*container.Node` from the tastora library, deploying it along side celestia/node/ev-node etc.

Initially we could just test the happy path, as triggering failure such as unsubmitted headers could be trickier. We could do things like kill the DA layer and verify metrics are exposed correctly.