build: partially revert AzCopy changes from 22c509f (#19092)

When we first transitioned to the `R1` network isolation
environment--which required us to _not_ contact
powershellgallery.com--we had to give up on the `AzureFileCopy` task.

Since then, the `AzurePowerShell` task has also become somewhat broken
while OneBranch fixed the issue that prevented us from using
`AzureFileCopy`.

In short, we now need to:

- Install the Azure PowerShell modules directly from our own feed (which
satisfies the network constraint)
- ... using `PSResourceGet` ...
- ... for Windows PowerShell 5.1 ...
- which is used by `AzureFileCopy` to later perform authentication.

.github/actions/spelling/expect/expect.txt

@@ -78,7 +78,6 @@ autoscrolling
 Autowrap
 AVerify
 awch
-AZCOPY
 azurecr
 AZZ
 backgrounded
@@ -1342,7 +1341,6 @@ PROPTITLE
 propvar
 propvariant
 psa
-PSCRED
 PSECURITY
 pseudoconsole
 psh

build/pipelines/templates-v2/job-deploy-to-azure-storage.yml

@@ -75,13 +75,30 @@ jobs:
       }
     displayName: "Wrangle Unpackaged builds into place, rename"
 
-  - task: AzurePowerShell@5
+  - task: PowerShell@2
+    displayName: Install Azure Modules from custom PowerShell Gallery Repo
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+    inputs:
+      pwsh: false # We are preparing modules for AzureFileCopy, which uses PowerShell 5.1
+      targetType: inline
+      script: |-
+        $MachineToken = $env:SYSTEM_ACCESSTOKEN | ConvertTo-SecureString -AsPlainText -Force
+        $Credential = [PSCredential]::new("ONEBRANCH_TOKEN", $MachineToken)
+        $MachineToken = $null
+        $Feed = "https://pkgs.dev.azure.com/shine-oss/terminal/_packaging/TerminalDependencies/nuget/v3/index.json"
+        Register-PSResourceRepository -Name "PSGalleryUpstream" -Uri $Feed -Trusted
+        Get-PSResourceRepository
+
+        Install-PSResource -Name Az.Accounts, Az.Storage, Az.Network, Az.Resources, Az.Compute -Repository "PSGalleryUpstream" -Credential $Credential
+
+  - task: AzureFileCopy@6
     displayName: Publish to Storage Account
     inputs:
+      sourcePath: _out/*
+      Destination: AzureBlob
       azureSubscription: ${{ parameters.subscription }}
-      azurePowerShellVersion: LatestVersion
+      storage: ${{ parameters.storageAccount }}
-      pwsh: true
+      ContainerName: ${{ parameters.storageContainer }}
-      ScriptType: InlineScript
+      AdditionalArgumentsForBlobCopy: "--content-type application/octet-stream"
-      Inline: |-
+
-        $Env:AZCOPY_AUTO_LOGIN_TYPE="PSCRED"
-        & AzCopy copy "_out\*" "https://${{ parameters.storageAccount }}.blob.core.windows.net/${{ parameters.storageContainer }}/" --content-type application/octet-stream