Test failure: `com.linecorp.armeria.client.endpoint.healthcheck.HealthCheckedEndpointGroupLongPollingPingTest.ping`

[schiemon]

Following test failed in build-windows-latest-jdk-21:

HealthCheckedEndpointGroupLongPollingPingTest > ping() FAILED
    java.lang.AssertionError: 
    Expecting size of:
      [[:status=102, armeria-lphc=60, 1]]
    to be greater than or equal to 2 but was 1
        at com.linecorp.armeria.client.endpoint.healthcheck.HealthCheckedEndpointGroupLongPollingPingTest.ping(HealthCheckedEndpointGroupLongPollingPingTest.java:125)

ref: https://github.com/line/armeria/actions/runs/17895694609/job/50882008490?pr=6398#step:10:1458