web: remove `percy` from e2e tests
Created by: valerybugakov
Context
As noticed in this comment we recently started successfully snapshotting in E2E tests. It caused all snapshots to disappear from the Percy diff on the main branch. Let's use Percy snapshots only in integration tests to avoid such situations, and confusion about multiple Percy builds. That's the only diff that we used before this PR, so it doesn't change anything from the confidence perspective.
Test plan
Check that percySnapshot is not called in web E2E tests.