feat: use private container registry for network isolated e2e tests

[AlisonB319]

What type of PR is this?

What this PR does / why we need it: For NIC e2e tests we want to make sure they are not using acs-mirror anywhere. After the move to oras installs, acs mirror should no longer be required for airgap tests

Which issue(s) this PR fixes:

Fixes #

Requirements:

• [ ] uses conventional commit messages
• [ ] includes documentation
• [ ] adds unit tests
• [ ] tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

[coveralls]

Pull Request Test Coverage Report for Build 11188451126

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 71.271%

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Totals
Change from base Build 11188295050:	0.0%
Covered Lines:	2590
Relevant Lines:	3634

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💛 - Coveralls

[AlisonB319]

All airgap e2e's are passing, e2e's just seem to be a bit unhappy in general atm.