fix: Fix finding machine images when no architecture is defined in th…

[matthias-horne]

…e cloud profile

How to categorize this PR?

/area control-plane
/kind bug
/platform openstack

What this PR does / why we need it:

When no architecture is defined for an image version in the cloud profile, it was no longer correctly found after merging #1222

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Release note:

[github-actions]

This change improves the OpenStack machine image architecture matching logic by making it more robust when handling undefined architecture values. Instead of using pointer equality checks that could fail with nil values, it now uses safe dereferencing with a default fallback to AMD64 architecture.

Walkthrough

• Bug Fix: Enhanced architecture matching in OpenStack machine image selection to handle cases where architecture is not explicitly defined, defaulting to AMD64 and preventing potential nil pointer issues during image flavor resolution.

_{Model: claude-sonnet-4-20250514 | Prompt Tokens: 725 | Completion Tokens: 104}

[gardener-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AndreasBurger

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[gardener-prow]

LGTM label has been added.

Details

Git tree hash: 4850dacdf407f8ec1bfe29543ebbe335a7ec73d9