Pilot Pester 6.0.0-rc1 in CI

Update tools/installPSResources.ps1 and the Windows PowerShell CI step to
install the Pester 6.0.0 release candidate so CI exercises Pester 6.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: nohwnd

.github/workflows/ci-test.yml

@@ -46,7 +46,7 @@ jobs:
       - name: Test Windows PowerShell
         if: matrix.os == 'windows-latest'
         run: |
-           Install-Module Pester -Scope CurrentUser -Force -SkipPublisherCheck
+           Install-Module Pester -RequiredVersion 6.0.0-rc1 -AllowPrerelease -Scope CurrentUser -Force -SkipPublisherCheck
            ./build.ps1 -Test -Verbose
         shell: powershell
 

tools/installPSResources.ps1

@@ -18,7 +18,8 @@ Install-PSResource -Verbose -TrustRepository -RequiredResource  @{
         repository = $PSRepository
     }
     Pester = @{
-        version = "5.7.1"
+        version = "6.0.0-rc1"
+        prerelease = $true
         repository = $PSRepository
     }
 }