feat: remove Equinix Metal (metalv1) from the SDK

[turegano-equinix]

Removes all Equinix Metal (metalv1) code ahead of its end-of-sale on June 30, 2026

[turegano-equinix]

None of the failing checks are caused by the metalv1 removal.

1. test (1.19.x) test-codegen (both jobs): Fails in the Generate step while applying a fabricv4 patch (20260128_fix_cloud_router_search_sort_criteria_enum.patch). The patch targets route_aggregation_sort_item.py and sort_item.py, which no longer exist. The Fabric code-gen renamed them to ra_attachment_sort_item.py and similar. That is why "2 out of 2 hunks ignored", which makes make generate-all exit with Error 2.

This is the same preexisting Fabric bug seen locally (the broken CHANGE_LOG_SLASH_... enum). The stale patch is exactly what produces that broken enum. This branch does not touch Fabric's patches/ or Makefile.fabricv4. It only removed patches/services/metalv1/.keep. The failure already exists on main.

2. integration-test-pr Ansible: This is the workflow removed in this PR, but it uses pull_request_target, so GitHub runs it from the base branch (main), not from the PR head. That is why it still runs. It will disappear once merged, since it no longer exists on main.

[ctreatma]

Looks good. I see that the Fabric generation issue exists elsewhere but was being masked by the successful Metal generation afterwards.