[5.1] Remove unused dependencies

[paulmedynski]

The MDS 6.1 .NET Framework project currently references the following packages:

Project 'Microsoft.Data.SqlClient' has the following package references
   [net462]:
   Top-level Package                                         Requested        Resolved
   > Azure.Core                                              [1.47.1,2.0.0)   1.47.1
   > Azure.Identity                                          1.14.2           1.14.2
   > Microsoft.Bcl.Cryptography                              8.0.0            8.0.0
   > Microsoft.Data.SqlClient.SNI                            6.0.2            6.0.2
   > Microsoft.Extensions.Caching.Memory                     8.0.1            8.0.1
   > Microsoft.IdentityModel.JsonWebTokens                   7.7.1            7.7.1
   > Microsoft.IdentityModel.Protocols.OpenIdConnect         7.7.1            7.7.1
   > Microsoft.NETFramework.ReferenceAssemblies        (A)   [1.0.3, )        1.0.3
   > System.Buffers                                          4.5.1            4.5.1
   > System.Security.Cryptography.Pkcs                       8.0.1            8.0.1
   > System.Text.Encodings.Web                               8.0.0            8.0.0
   > System.Text.Json                                        8.0.5            8.0.5

Microsoft.Bcl.Cryptography and System.Text.Encodings.Web are referenced, but I can't find any use of them in the code. They should be removed from the project.

Audit all of the projects whose artifacts we publish in NuGet packages for unused dependencies, on main and the 3 servicing branches (6.1, 6.0. 5.1).