Pin major Pester version to 4 to prevent breaking changes caused by upcoming release of v5 (#12262)

.vsts-ci/misc-analysis.yml

@@ -34,7 +34,7 @@ jobs:
     condition: succeededOrFailed()
 
   - powershell: |
-      Install-module pester -Scope CurrentUser -Force
+      Install-module Pester -Scope CurrentUser -Force -MaximumVersion 4.99
     displayName: Install Pester
     condition: succeededOrFailed()
 

.vsts-ci/templates/nanoserver.yml

@@ -34,7 +34,7 @@ jobs:
     continueOnError: true
 
   - pwsh: |
-      Install-module pester -Scope CurrentUser -Force
+      Install-module Pester -Scope CurrentUser -Force -MaximumVersion 4.99
     displayName: 'Install Pester'
     continueOnError: true
 

build.psm1

@@ -689,7 +689,7 @@ function Restore-PSPester
         [ValidateNotNullOrEmpty()]
         [string] $Destination = ([IO.Path]::Combine((Split-Path (Get-PSOptions -DefaultToNew).Output), "Modules"))
     )
-    Save-Module -Name Pester -Path $Destination -Repository PSGallery -RequiredVersion "4.8.0"
+    Save-Module -Name Pester -Path $Destination -Repository PSGallery -MaximumVersion 4.99
 }
 
 function Compress-TestContent {

tools/ci.psm1

@@ -492,8 +492,9 @@ function Invoke-CIFinish
         $env:PSMsiX64Path = $artifacts | Where-Object { $_.EndsWith(".msi")}
 
         # Install the latest Pester and import it
-        Install-Module Pester -Force -SkipPublisherCheck
-        Import-Module Pester -Force
+        $maximumPesterVersion = '4.99'
+        Install-Module Pester -Force -SkipPublisherCheck -MaximumVersion $maximumPesterVersion
+        Import-Module Pester -Force -MaximumVersion $maximumPesterVersion
 
         # start the packaging tests and get the results
         $packagingTestResult = Invoke-Pester -Script (Join-Path $repoRoot '.\test\packaging\windows\') -PassThru