Is your feature request related to a problem? Please describe.
For nugetconfig binary caching sources, vcpkg passes -ApiKey AzureDevOps as an option to the nuget push command, which overrides the API key specified in the nuget config file. This prevents pushing to corporate nuget repositories that require specific credentials.

Proposed solution
Remove -ApiKey AzureDevOps from the nuget push command for nugetconfig sources, or provide a vcpkg flag that causes it to be left off or overwritten with the real API key.

Describe alternatives you've considered
Add a write-only nuget binary source pointing at a temporary local directory, and then, after running vcpkg install, run a separate nuget command manually without the -ApiKey flag. This has at least a few disadvantages: more complicated config for separate read and write sources, requiring an extra step to upload and then cleanup files vs. it happening automatically, and not being able to rely on the copy of nuget vcpkg downloads for itself to use.