Update dependencies from https://github.com/dotnet/arcade build 20210…

…205.5

Microsoft.DotNet.Arcade.Sdk
 From Version 6.0.0-beta.20630.2 -> To Version 6.0.0-beta.21105.5

eng/Version.Details.xml

@@ -3,9 +3,9 @@
   <ProductDependencies>
   </ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="6.0.0-beta.21101.7">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="6.0.0-beta.21105.5">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>2b430e5bbfaec37a6cead2f0cf79157f01f1a623</Sha>
+      <Sha>fc83e59329203724d4a63c4f6c843be62983a35e</Sha>
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>

eng/common/dotnet-install.sh

@@ -49,13 +49,8 @@ while [[ $# > 0 ]]; do
   shift
 done
 
-# Use uname to determine what the CPU is.
-cpuname=$(uname -p)
-# Some Linux platforms report unknown for platform, but the arch for machine.
-if [[ "$cpuname" == "unknown" ]]; then
-  cpuname=$(uname -m)
-fi
-
+# Use uname to determine what the CPU is, see https://en.wikipedia.org/wiki/Uname#Examples
+cpuname=$(uname -m)
 case $cpuname in
   aarch64)
     buildarch=arm64

global.json

@@ -3,6 +3,6 @@
     "dotnet": "5.0.100"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "6.0.0-beta.21101.7"
+    "Microsoft.DotNet.Arcade.Sdk": "6.0.0-beta.21105.5"
   }
 }