chore: Fixed wrong version of NuGet in CI

azure-pipelines.iOS.yml

@@ -62,7 +62,7 @@ jobs:
 
   - task: NuGetToolInstaller@0
     inputs:
-      versionSpec: 4.9.1
+      versionSpec: 6.1.0
 
   - task: NuGetCommand@2
     inputs:

azure-pipelines.yml

@@ -55,7 +55,7 @@ jobs:
 
     - task: NuGetToolInstaller@0
       inputs:
-        versionSpec: 4.9.1
+        versionSpec: 6.1.0
 
     - task: DownloadSecureFile@1
       condition: eq(variables['BuildPlatform'], 'Android')