Update the default Azure VM size from the legacy Standard_D4s_v3 to a current supported VM size (Standard_D4s_v5) across the HyperShift codebase.

Why

The current default VM size Standard_D4s_v3 is a legacy Azure VM size that Microsoft is phasing out. We need to update to a newer v5-series generation to ensure:

• Continued Azure support and compatibility
• Better performance characteristics
• Alignment with current Azure best practices

Acceptance Criteria

• Default Azure VM size updated from Standard_D4s_v3 to Standard_D4s_v5 in cluster creation code
• Default Azure VM size updated from Standard_D4s_v3 to Standard_D4s_v5 in nodepool creation code
• All test fixtures updated to reflect new default VM size
• E2E tests updated and passing with new VM size
• Vendor dependencies updated if needed
• Code passes make lint-fix and make verify
• Documentation updated if VM size requirements are documented

Technical Details

Files to Modify

• cmd/cluster/azure/create.go - Update default VM size constant/variable
• cmd/nodepool/azure/create.go - Update default VM size constant/variable
• cmd/nodepool/azure/create_test.go - Update test expectations
• hypershift-operator/controllers/nodepool/azure_test.go - Update controller tests
  _ cmd/cluster/azure/testdata/zz_fixture__.yaml - Update all test fixtures
• test/e2e/azure_scheduler_test.go - Update E2E tests
• test/e2e/create_cluster_test.go - Update E2E tests
• test/e2e/nodepool_rolling_upgrade_test.go - Update E2E tests
• test/e2e/v2/tests/api_ux_validation_test.go - Update validation tests

Approach

• Search for all occurrences of Standard_D4s_v3
• Replace with Standard_D4s_v5
• Update test fixtures using make api if needed
• Run make lint-fix and make verify
• Run Azure E2E tests to validate

Migration Path

Standard_D4s_v3 (legacy v3-series) → Standard_D4s_v5 (current v5-series)

VM Specs:

• vCPU count: 4 (same)
• Memory: 16 GiB (same)
• Generation: v3 (legacy) → v5 (current)
• Benefits: Better performance in v5-series