Move from rc1 to rtm prerelease label

Author: RussKeldorph

dependencies.props

@@ -18,7 +18,7 @@
     <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">false</StabilizePackageVersion>
     <StableVersion Condition="'$(StabilizePackageVersion)' == 'true' and '$(StableVersion)' == ''">$(PackageVersion)</StableVersion>
 
-    <PreReleaseLabel>rc1</PreReleaseLabel>
+    <PreReleaseLabel>rtm</PreReleaseLabel>
   </PropertyGroup>
 
   <!-- Source of truth for dependency tooling: the commit hash of the dotnet/versions master branch as of the last auto-upgrade. -->