Loosens the connector route assertion to allow concurrent tests against
the same tailnet to more reliably pass, while still asserting the
client itself is advertising those routes and they're recognised in the
API.
Also make createOrUpdate more resilient to a test that didn't fully tear
down on the same cluster previously. By respecting the existing resource
version and finalizers, we can update resources that didn't get deleted
from a previous run.
Updates tailscale/corp#45426
Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>