2.1.0 Release! (#1394)

This bumps versioning for the 2.1.0 release, ready to GA!

Directory.Build.props

@@ -13,7 +13,7 @@
     <NoWarn>NU5105</NoWarn>
     <PackageReleaseNotes>https://stackexchange.github.io/StackExchange.Redis/ReleaseNotes</PackageReleaseNotes>
     <PackageProjectUrl>https://github.com/StackExchange/StackExchange.Redis/</PackageProjectUrl>
-    <PackageLicenseUrl>https://raw.github.com/StackExchange/StackExchange.Redis/master/LICENSE</PackageLicenseUrl>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
 
     <LangVersion>8.0</LangVersion>
     <RepositoryType>git</RepositoryType>

docs/ReleaseNotes.md

 # Release Notes
 
-## 2.1.0-preview
+## 2.1.0
 
 - fix: ensure active-message is cleared (#1374 via hamish-omny)
 - add: sentinel support (#1067 via shadim; #692 via lexxdark)

version.json

 {
-  "version": "2.1.0-preview.{height}",
+  "version": "2.1.0",
   "assemblyVersion": "2.0",
   "publicReleaseRefSpec": [
     "^refs/heads/master$",