(cleanup): remove unused volume handling

[cartermckinnon]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

This removes dead code associated with EBS volumes. This is old code from the legacy in-tree AWS provider, and has never been used in the AWS CCM. I sanity checked that it is not being used by the EBS or EFS CSI driver projects, and I don't see any usage searching around on grep.app.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Legacy volume handling has been removed.

[k8s-ci-robot]

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[cartermckinnon]

/assign @mmerkes

[mmerkes]

/lgtm /approve

Tx for cleaning this up! Can believe we had so much dead code in here.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mmerkes

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