🐛 Prevent orphaned InfrastructureMachines

[fabriziopandini]

What this PR does / why we need it:
This PR prevents CAPI to leave orphaned InfrestructureMachines when a MachineSet creates a machine that gets deleted before the controllers setting ownerRef to the corresponding InfrastructureMachines.

This is achieved by setting an additional ownerRef to the MachineSet, thus triggering InfrestructureMachines cleanup when the MS gets deleted.

Which issue(s) this PR fixes:
Fixes #5483

[fabriziopandini]

/test pull-cluster-api-e2e-full-main

[enxebre]

/lgtm

[vincepri]

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: vincepri

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[fabriziopandini]

Q: should we backport this? @vincepri @sbueringer

[srm09]

I see benefit in backporting this change to the earlier releases. I have seen this issue prop up in multiple environments using previous versions. Plus the change only adds another owner ref without affecting the flow of object reconciliation.
👍🏾 from my side.

[fabriziopandini]

/cherry-pick release-1.0

[k8s-infra-cherrypick-robot]

@fabriziopandini: new pull request created: #5875

In response to this:

/cherry-pick release-1.0

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