Bump System.Text.Encodings.Web

Bumps [System.Text.Encodings.Web](https://github.com/dotnet/corefx) from 4.7.0 to 4.7.2.
- [Release notes](https://github.com/dotnet/corefx/releases)
- [Commits](https://github.com/dotnet/corefx/commits)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

samples/DotNet/Azure.Messaging.EventHubs/ManagedIdentityWebApp/packages.config

@@ -25,7 +25,7 @@
   <package id="System.Security.Cryptography.Primitives" version="4.3.0" targetFramework="net472" />
   <package id="System.Security.Cryptography.ProtectedData" version="4.7.0" targetFramework="net472" />
   <package id="System.Security.Cryptography.X509Certificates" version="4.3.2" targetFramework="net472" />
-  <package id="System.Text.Encodings.Web" version="4.7.0" targetFramework="net472" />
+  <package id="System.Text.Encodings.Web" version="4.7.2" targetFramework="net472" />
   <package id="System.Text.Json" version="4.7.0" targetFramework="net472" />
   <package id="System.Threading.Channels" version="4.7.0" targetFramework="net472" />
   <package id="System.Threading.Tasks.Extensions" version="4.6.0-preview.18571.3" targetFramework="net472" />