[Breaking change]: New version of some OOB packages

[carlossanlop]

Description

We generated new versions of some OOB packages, but their source code did not change. Instead, we made some changes that can be considered breaking:

• The TFMs the packages support were updated
• We updated the package version minor number.
• In some cases, we stopped supporting some TFMs.

Additionally, we migrated the source code of these packages from their old location, which was a branch of .NET that is no longer in support, to the dotnet/maintenance-packages repo.

Package	Old source code location	New package version
Microsoft.Bcl.HashCode	dotnet/corefx, 3.1 branch	6.0.0
Microsoft.IO.Redist	dotnet/runtime, 6.0 branch	6.1.0
System.Buffers	dotnet/corefx, 2.1 branch	4.6.0
System.Data.SqlClient	dotnet/corefx, 3.1 branch	4.9.0
System.Json	dotnet/corefx, 3.1 branch	4.8.0
System.Memory	dotnet/corefx, 2.1 branch	4.6.0
System.Net.WebSockets.WebSocketProtocol	dotnet/runtime, 5.0 branch	5.1.0
System.Numerics.Vectors	dotnet/corefx, 2.1 branch	4.6.0
System.Reflection.DispatchProxy	dotnet/corefx, 3.1 branch	4.8.0
System.Runtime.CompilerServices.Unsafe	dotnet/runtime, 6.0 branch	6.1.0
System.Threading.Tasks.Extensions	dotnet/corefx, 2.1 branch	4.6.0
System.Xml.XPath.XmlDocument	dotnet/corefx, 1.1 branch	4.7.0

cc @ViktorHofer @ericstj

Version

Other (please put exact version in description textbox)

Previous behavior

Some TFMs targeted by the old packages are already out of support.

New behavior

No source code changes, but the TFMs were updated.

Type of breaking change

• Binary incompatible: Existing binaries might encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.
• Source incompatible: When recompiled using the new SDK or component or to target the new runtime, existing source code might require source changes to compile successfully.
• Behavioral change: Existing binaries might behave differently at run time.

Reason for change

Move the source code of these packages from their old branch which was already out of support to a repo that is actively maintained.

Recommended action

Depending on the package, different recommended actions are provided: https://github.com/dotnet/maintenance-packages/tree/main/package-support-policy.md

NOTE: This document is still under review so it doesn't yet exist in main, but the PR is almost ready to get merged: dotnet/maintenance-packages#76

Feature area

Core .NET libraries

Affected APIs

All that are contained in the packages.