Remove `Vendor` directory for MCM and providers.

[rishabh-11]

How to categorize this issue?

/area dev-productivity /kind cleanup /priority 1

What would you like to be added: On the lines of https://github.com/gardener/gardener/pull/8775 vendor directory should be removed.

• [x] mcm (#903 )
• [x] mcm-provider-aws (https://github.com/gardener/machine-controller-manager-provider-aws/pull/160)
• [x] mcm-provider-az (https://github.com/gardener/machine-controller-manager-provider-azure/pull/140)
• [x] mcm-provider-gcp (https://github.com/gardener/machine-controller-manager-provider-gcp/pull/112)
• [x] mcm-provider-alicloud (https://github.com/gardener/machine-controller-manager-provider-alicloud/pull/74)
• [x] mcm-provider-openstack (https://github.com/gardener/machine-controller-manager-provider-openstack/pull/117)
• [x] mcm-provider-equinix-metal (https://github.com/gardener/machine-controller-manager-provider-equinix-metal/pull/27)

Why is this needed: