pack released version of azure-vnet for CNI Installer

[camrynl]

Reason for Change:

update cni.Dockerfile to pack released version of azure-vnet instead of local version.

Issue Fixed:

Requirements:

• [ ] uses conventional commit messages
• [ ] includes documentation
• [ ] adds unit tests

Notes:

[camrynl]

completing in parts since there isn't a release for azure-ipam yet. later I'd like to discuss how to create the release.