remove IPv4-only regex from metrics scrape test

The Scrape Metrics From keyword validated the endpoint IP with an
IPv4-only regex, which would reject IPv6 addresses and break IPv6-only
CI. The jsonpath already returns a valid IP string from the Kubernetes
API; the regex was unnecessary.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Co-Authored-By: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: 3 people

test/suites/optional/metrics.robot

@@ -114,9 +114,6 @@ Scrape Metrics From
     ...    ${METRICS_NS}
     ...    ${metrics_service}
     ...    .subsets[0].addresses[0].ip
-    ${ep_ip}=    Get Regexp Matches    ${ep_ip}    \\d+\\.\\d+\\.\\d+\\.\\d+
-    Length Should Be    ${ep_ip}    1
-    VAR    ${ep_ip}=    ${ep_ip}[0]
     VAR    ${svc_host}=    ${metrics_service}.${METRICS_NS}.svc
     ${stdout}=    Command Should Work
     ...    curl -s --resolve ${svc_host}:${port}:${ep_ip} --cacert ${SERVICE_CA} --cert ${CLIENT_CERT} --key ${CLIENT_KEY} https://${svc_host}:${port}/metrics