Unpin <MicrosoftExtensions.Configuration.Azure.KeyVault (dotnet#27957)

Author: mmitche

build/dependencies.props

@@ -4,6 +4,7 @@
     <!-- MicrosoftNETCoreApp21PackageVersion is assigned at the bottom so it can automatically pick up MicrosoftNETCoreAppPackageVersion in an orchestrated build. -->
     <MicrosoftNETCoreAppPackageVersion>2.1.23</MicrosoftNETCoreAppPackageVersion>
     <MicrosoftNETCoreDotNetAppHostPackageVersion>2.1.23</MicrosoftNETCoreDotNetAppHostPackageVersion>
+    <MicrosoftExtensionsConfigurationAzureKeyVaultPackageVersion>2.1.1</MicrosoftExtensionsConfigurationAzureKeyVaultPackageVersion>
   </PropertyGroup>
 
   <Import Project="$(DotNetPackageVersionPropsPath)" Condition="'$(DotNetPackageVersionPropsPath)' != ''" />
@@ -30,7 +31,6 @@
     <MicrosoftExtensionsCachingSqlServerPackageVersion>2.1.2</MicrosoftExtensionsCachingSqlServerPackageVersion>
     <MicrosoftExtensionsCommandLineUtilsSourcesPackageVersion>2.1.1</MicrosoftExtensionsCommandLineUtilsSourcesPackageVersion>
     <MicrosoftExtensionsConfigurationAbstractionsPackageVersion>2.1.1</MicrosoftExtensionsConfigurationAbstractionsPackageVersion>
-    <MicrosoftExtensionsConfigurationAzureKeyVaultPackageVersion>2.1.1</MicrosoftExtensionsConfigurationAzureKeyVaultPackageVersion>
     <MicrosoftExtensionsConfigurationBinderPackageVersion>2.1.10</MicrosoftExtensionsConfigurationBinderPackageVersion>
     <MicrosoftExtensionsConfigurationCommandLinePackageVersion>2.1.1</MicrosoftExtensionsConfigurationCommandLinePackageVersion>
     <MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>2.1.1</MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>