.net 5 requires 5.8

talked to Matteo Pagani, this should be the fix

.pipelines/ci/templates/build-powertoys-steps.yml

@@ -8,9 +8,9 @@ steps:
   clean: true
 
 - task: NuGetToolInstaller@0
-  displayName: Ensure NuGet 5.5.0
+  displayName: Ensure NuGet 5.8.0
   inputs:
-    versionSpec: 5.5.0
+    versionSpec: 5.8.0
 
 - task: VisualStudioTestPlatformInstaller@1
   displayName: Ensure VSTest Platform
@@ -105,4 +105,4 @@ steps:
       **\UnitTests-SvgPreviewHandler.dll
       **\powerpreviewTest.dll
       !**\obj\**
-#      **\PowerRenameUnitTests.dll
+#      **\PowerRenameUnitTests.dll