[GEP-33] Allow mixed format Capability CloudProfiles

[Roncossek]

How to categorize this PR?
/area control-plane
/kind enhancement
/platform aws

What this PR does / why we need it:

This PR enables mixed format support for machine image specifications in CloudProfile and NamespacedCloudProfile resources, allowing smooth migration from the legacy architecture-per-region format to the new capabilityFlavors format.

Background:
Previously, CloudProfiles could only use one format per profile:

• Old format: regions with architecture field per region
• New format: capabilityFlavors with capabilities (introduced in GEP-33)

This created a breaking change scenario where users had to migrate all image versions at once.

Changes:

1. CloudProfile Support: When spec.machineCapabilities is defined, both old and new formats are now supported per image version

   • Validation accepts both formats
   • Each version can use either format independently

2. NamespacedCloudProfile Support: Removes format transformation to parent CloudProfile format

   • Mixed format is preserved as-is
   • Validation handles both formats

3. Image Selection Logic: Updated to handle both formats during worker/bastion machine image selection

   • Automatically converts old format regions to capabilityFlavors internally
   • Maintains backward compatibility for non-capabilities CloudProfiles

Example:

providerConfig:
  machineImages:
    - name: ubuntu
      versions:
        # New format - with capabilities
        - version: "24.04"
          capabilityFlavors:
            - capabilities:
                architecture: [amd64]
                hypervisor: [baremetal, xen]
              regions:
                - name: eu-west-1
                  ami: ami-456
        # Old format - backwards compatible
        - version: "22.04"
          regions:
            - name: eu-west-1
              ami: ami-123
              architecture: amd64

Which issue(s) this PR fixes:
Part of gardener/gardener#11301

Special notes for your reviewer:
@hebelsan

Release note:

Support mixed format for machine image specifications in CloudProfile and NamespacedCloudProfile, allowing both (legacy) architecture-per-region format and new capabilityFlavors format to coexist within the same CloudProfile for smooth migration.

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[AndreasBurger]

lgtm
rebased, merging

[github-actions]

This change implements mixed format support for AWS cloud profile machine images, allowing both legacy (regions with architecture) and new capability-based formats to coexist. The implementation adds backwards compatibility while transitioning to the modern capability-based architecture selection system.

Walkthrough

• New Feature: Added support for mixed format machine image configurations, allowing CloudProfiles to use both old format (regions with architecture) and new format (capabilityFlavors) simultaneously per version
• New Feature: Introduced capability normalization functions to ensure consistent architecture handling across legacy and modern formats
• Refactor: Simplified validation and mutation logic by removing format transformation helper functions and supporting mixed formats directly
• Refactor: Updated machine image selection in worker controller to use normalized capabilities for consistent architecture resolution
• Test: Added comprehensive test coverage for mixed format scenarios, old format validation, and capability normalization edge cases
• Chore: Removed deprecated helper functions for format transformation that are no longer needed with native mixed format support

_{Model: claude-sonnet-4-20250514 | Prompt Tokens: 32844 | Completion Tokens: 219}

[gardener-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AndreasBurger

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Needs approval from an approver in each of these files:

• OWNERS [AndreasBurger]

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[gardener-prow]

LGTM label has been added.

Details

Git tree hash: 719ecdaf2da4ffa9c058429782f97e0cff36a9c1