update-dependencies can only access publicly available .NET checksums/shas

[lbussell]

Related:

• Redesign update-dependencies tool to better support internal builds #6305
• Add staging pipeline support to update-dependencies tool #6473

The dependency update code for acquiring checksums should be refactored so that it can use the checksum files from the staging storage account.

Thanks to #6473, we can now use a service connection to access the staging storage account. However, the code in SpecificCommand (which does the checksum updates/calculation) has no knowledge of the storage account yet.

This does not affect releases because .NET checksums are publicly available several days before a release goes live. This mostly impacts release validation and staging because those need to happen before the release is finalized.

[lbussell]

If we implemented Consider updating SHA checks to new SHA files (#6495), we would not need to access shas at all in the update-dependencies tool.

[lbussell]

[Triage] This issue is about not being able to get checksums from the internal storage account while running the dependency update tooling. With #6495, we are now going to download checksums during Dockerfile builds. Since we already have an access token during internal Dockerfile builds, this issue can be closed. We won't need to get checksums during the update-dependencies step.