clean up old runtimes (#27665)

Co-authored-by: Yeming Liu <[email protected]>

Author: isra-fel

tools/CleanupBuild.ps1

@@ -76,7 +76,7 @@ foreach($RMPath in $resourceManagerPaths)
         Import-LocalizedData -BindingVariable ModuleMetadata -BaseDirectory $psd1.DirectoryName -FileName $psd1.Name
 
         $acceptedDlls = @(
-            # netcoreapp, can't be in RequiredAssemblies, but we need to pack it
+            # not targeting netstandard2.0, can't be in RequiredAssemblies, but we need to pack it
             "Microsoft.Azure.PowerShell.AuthenticationAssemblyLoadContext.dll",
             # customized AutoMapper
             "Microsoft.Azure.PowerShell.AutoMapper.dll",
@@ -113,7 +113,7 @@ foreach($RMPath in $resourceManagerPaths)
 
         Write-Host "Removing redundant dlls in $($RMFolder.Name)"
         $removedDlls = Get-ChildItem -Path $RMFolder.FullName -Filter "*.dll" -Recurse | where { $acceptedDlls -notcontains $_.Name -and !$_.FullName.Contains("Assemblies") }
-        # do not remove lib dlls (for example Az.Accounts/lib/netcoreapp2.1/Azure.Core.dll)
+        # do not remove lib dlls (for example Az.Accounts/lib/netstandard2.0/Azure.Core.dll)
         $libPattern = [System.IO.Path]::DirectorySeparatorChar + "lib" + [System.IO.Path]::DirectorySeparatorChar;
         $removedDlls = $removedDlls | Where-Object { -not $_.FullName.Contains($libPattern) }
         $removedDlls | % { Write-Host "Removing $($_.Name)"; Remove-Item $_.FullName -Force }

tools/Tools.Common/Loaders/SharedAssemblyLoader.cs

@@ -1,18 +1,28 @@
-using System;
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Reflection;
-using System.Text;
 
 namespace Tools.Common.Loaders
 {
     public class SharedAssemblyLoader
     {
-        private const string NetCoreApp21 = "netcoreapp2.1";
-        private const string NetCoreApp31 = "netcoreapp3.1";
         private const string NetStandard20 = "netstandard2.0";
-        private static readonly IEnumerable<string> Frameworks = new string[] { NetCoreApp21, NetCoreApp31, NetStandard20 };
+        private static readonly IEnumerable<string> Frameworks = new string[] { NetStandard20 };
         public static HashSet<string> ProcessedFolderSet = new HashSet<string>();
 
         public static void Load(string directory)