chore: fix a flake
chore: fix a flake

we're configuring the router multiple times. it goes like this:

1. `cy.configureCluster({mesos: "1-for-each-health"})`
2. `cy.visitUrl("/nodes/agents/grid")`
3. `cy.configureCluster({ mesos: "no-agents" })`

And only the last call overrides the routes to respond with a empty
"state-summary". Depending on how fast our app loads, we have a race condition
here! :tada:

dcos/dcos-ui,dcos/dcos-ui,dcos/dcos-ui,dcos/dcos-ui,dcos/dcos-ui