Don't use property for msbuild versions in Versions.props (#114298)

Avoids issues with source-build overwriting them.

Author: akoeplinger

eng/Versions.props

@@ -187,9 +187,9 @@
     <MicrosoftDiagnosticsToolsRuntimeClientVersion>1.0.4-preview6.19326.1</MicrosoftDiagnosticsToolsRuntimeClientVersion>
     <DNNEVersion>2.0.5</DNNEVersion>
     <MicrosoftBuildVersion>17.8.3</MicrosoftBuildVersion>
-    <MicrosoftBuildTasksCoreVersion>$(MicrosoftBuildVersion)</MicrosoftBuildTasksCoreVersion>
-    <MicrosoftBuildFrameworkVersion>$(MicrosoftBuildVersion)</MicrosoftBuildFrameworkVersion>
-    <MicrosoftBuildUtilitiesCoreVersion>$(MicrosoftBuildVersion)</MicrosoftBuildUtilitiesCoreVersion>
+    <MicrosoftBuildTasksCoreVersion>17.8.3</MicrosoftBuildTasksCoreVersion>
+    <MicrosoftBuildFrameworkVersion>17.8.3</MicrosoftBuildFrameworkVersion>
+    <MicrosoftBuildUtilitiesCoreVersion>17.8.3</MicrosoftBuildUtilitiesCoreVersion>
     <NugetFrameworksVersion>6.2.4</NugetFrameworksVersion>
     <NugetProjectModelVersion>6.2.4</NugetProjectModelVersion>
     <NugetPackagingVersion>6.2.4</NugetPackagingVersion>