#4458 accidentally left `continue-on-error: true` in the workflow.
This meant that E2E test failures weren't reported as check failures.

This test was a strict subset of `deployments.test.ts`, and wasn't
providing any additional value.

This warning may not be shown if an account has opted-in to standard
pricing. This change normalises output to remove it, meaning tests
can be run on any account, regardless of opt-in state.

#4571 updated the message logged in non-interactive contexts for
default values to use the word `fallback` instead of `default`.

Some messages were being logged before the `--log-level` argument was
applied. In particular, this meant the "writing logs to" message at
`debug` level, was not output when using `--log-level=debug`.

This change makes a few improvements to `dev.test.ts`:

- Shorter timeouts for `fetch()` retries
- Replaces `get-port` with native port `0` implementation
- Waits for stdout handlers to be registered before starting
  `wrangler dev`
- Ignores errors if we failed to find a proccess to kill
  (assumes the process was already killed)

These errors should not be reported to Sentry.