Clean up MCM RBAC resources migration logic

[georgibaltiev]

How to categorize this PR?

/area security
/kind cleanup
/platform azure

What this PR does / why we need it:

With the following PR, a migration runnable has been added to the PR, in order to remove RBAC resources that were no longer in use. These migrations were intended to be kept until the release of version 1.55.0.

This PR cleans up the migrations.

Which issue(s) this PR fixes:
NONE

Special notes for your reviewer:
NONE

Release note:

[github-actions]

This pull request removes temporary migration code that was scheduled for deletion after the v1.55.0 release. The change cleans up logic responsible for purging obsolete ClusterRole and ClusterRoleBinding resources for the machine-controller-manager. This improves code maintainability by removing deprecated code and has no impact on current functionality.

Walkthrough

• Chore: Removed a one-time migration task from the application startup. This task was responsible for cleaning up obsolete RBAC resources. This is a routine code cleanup that improves maintainability by removing logic that is no longer necessary, with no direct impact on end-users.

_{Model: gemini-2.5-pro | Prompt Tokens: 1185 | Completion Tokens: 128}

[kon-angelo]

@georgibaltiev can this be undrafted now?

[georgibaltiev]

I will open the PR for review once version v1.55.0 has been released.

[kon-angelo]

It should be up https://github.com/gardener/gardener-extension-provider-azure/releases/tag/v1.55.0 🤔

[georgibaltiev]

Oh, I see now. For some reason v1.54.2 has been marked as latest, so I assumed that v1.55.0 has not been released yet.

[kon-angelo]

We had to make a patch release for the previous version too that came later than v1.55 😅

[kon-angelo]

/lgtm