flake: e2e tests

[LukeAVanDrie]

Flaky e2e test failed in a PR that only touched isolated unit testing code.

See: https://prow.k8s.io/view/gs/kubernetes-ci-logs/pr-logs/pull/kubernetes-sigs_gateway-api-inference-extension/2014/pull-gateway-api-inference-extension-test-e2e-main/2001196577934282752

InferencePool when The Inference Extension is running [It] Should expose EPP metrics after generating traffic
/home/prow/go/src/sigs.k8s.io/gateway-api-inference-extension/test/e2e/epp/e2e_test.go:197
  [FAILED] Timed out after 180.004s.
  Expected success, but got an error:
      <*errors.errorString | 0xc00043a1a0>: 
      expected metric inference_objective_request_total not found in metrics output
      {
          s: "expected metric inference_objective_request_total not found in metrics output",
      }
  In [It] at: /home/prow/go/src/sigs.k8s.io/gateway-api-inference-extension/test/e2e/epp/e2e_test.go:489 @ 12/17/25 07:55:32.62