Install powershell/azure-cli from AzLinux native package feed

[mthalman]

Fixes #1269

The reason I'm fixing this now is because there's an issue with PMC when targeting https://packages.microsoft.com/config/rhel/8/packages-microsoft-prod.rpm:

 > [3/4] RUN curl -sSL -O https://packages.microsoft.com/config/rhel/8/packages-microsoft-prod.rpm &&     rpm -i packages-microsoft-prod.rpm &&     rm -f packages-microsoft-prod.rpm &&     tdnf update -y &&     tdnf install -y --setopt tsflags=nodocs          powershell &&     rm /etc/yum.repos.d/microsoft-prod.repo &&     tdnf clean all:
0.297 warning: packages-microsoft-prod.rpm: Header V4 RSA/SHA256 Signature, key ID be1229cf: NOKEY
1.844 Loaded plugin: tdnfrepogpgcheck
1.892 Refreshing metadata for: 'Microsoft Production'
2.026 repo md signature check: No public key
2.026 Error: TDNFVerifySignature 2004
2.026 Plugin error: repogpgcheck plugin error: failed to verify signature
2.026 
2.026 Error(2004) : Unknown error 404
2.027 Error: Failed to synchronize cache for repo 'Microsoft Production'
2.027 Error(2004) : Unknown error 404

This avoids that by getting the packages directly from the native feed.

[MichaelSimons]

Nice!