Update .NET SDK to 6.0.100-rc.2.21430.28 (#35948)

eng/Workarounds.props

@@ -25,6 +25,11 @@
     <UseSharedCompilation>true</UseSharedCompilation>
   </PropertyGroup>
 
+  <!-- Workaround continued use of netcoreapp2.1. -->
+  <PropertyGroup>
+    <NoWarn>$(NoWarn);NETSDK1138;CS8969</NoWarn>
+  </PropertyGroup>
+
   <PropertyGroup>
     <!-- Ignore warning about calling the Pack target on Web SDK projects. Our build scripts call /t:pack on everything in this repo. -->
     <WarnOnPackingNonPackableProject>false</WarnOnPackingNonPackableProject>

global.json

 {
   "sdk": {
-    "version": "6.0.100-rc.1.21415.3"
+    "version": "6.0.100-rc.2.21430.28"
   },
   "tools": {
-    "dotnet": "6.0.100-rc.1.21415.3",
+    "dotnet": "6.0.100-rc.2.21430.28",
     "runtimes": {
       "dotnet/x64": [
         "2.1.27",