Drop Support Equinix Metal cloud provider support

[KhizerRehan]

What this PR does / why we need it:
This PR drops Equinix Metal cloud provider support, including the Packet backward-compatibility shim, aligning machine-controller with the deprecation already in progress across the dashboard and kubermatic repositories.

FYI: This cloud provider has been deprecated in v2.29

Dashboard Repo

• https://github.com/kubermatic/dashboard/pull/7533/changes

Kubermatic Repo

• https://github.com/kubermatic/kubermatic/pull/15317/changes
• https://github.com/kubermatic/kubermatic/pull/14827/changes
• https://github.com/kubermatic/kubermatic/pull/15064/changes

Which issue(s) this PR fixes:

Fixes #

What type of PR is this?
/kind chore
/kind cleanup

Special notes for your reviewer:

Does this PR introduce a user-facing change? Then add your Release Note here:

  Removed Equinix Metal (Packet) cloud provider support from machine-controller.

Documentation:

NONE

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[KhizerRehan]

/retest

[KhizerRehan]

/test pull-machine-controller-e2e-gce

[kubermatic-bot]

@KhizerRehan: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-machine-controller-e2e-gce	dcee2c0	link	true	/test pull-machine-controller-e2e-gce

Full PR test history

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