Update deployment workflow for final HSM solution

This applies the changes from the separate Windows HSM signing prototype development to the official deployment workflow including:

1. Use of Azure Code Signing client
2. Sourcing signtool.exe from runner
3. Moving from batch to PowerShell for Windows signing script
4. Using the same signing process for .exe and .msi

.goreleaser.yml

@@ -41,7 +41,7 @@ builds:
     hooks:
       post:
         - cmd: >-
-            {{ if eq .Runtime.Goos "windows" }}.\script\sign{{ else }}./script/sign{{ end }} '{{ .Path }}'
+            {{ if eq .Runtime.Goos "windows" }}pwsh .\script\sign.ps1{{ else }}./script/sign{{ end }} '{{ .Path }}'
           output: true
     binary: bin/gh
     main: ./cmd/gh