Dependency update / fixes / skrungle bungle (#23745)

* Give .props files 2-space indents.

* Move to Central Package Management.

Allows us to store NuGet package versions all in one place. Yay!

* Update NuGet packages and fix code for changes.

Notable:

Changes to ILVerify.
Npgsql doesn't need hacks for inet anymore, now we need hacks to make the old code work with this new reality.
NUnit's analyzers are already complaining and I didn't even update it to 4.x yet.
TerraFX changed to GetLastSystemError so error handling had to be changed.
Buncha APIs have more NRT annotations.

* Remove dotnet-eng NuGet package source.

I genuinely don't know what this was for, and Central Package Management starts throwing warnings about it, so YEET.

* Remove Robust.Physics project.

Never used.

* Remove erroneous NVorbis reference.

Should be VorbisPizza and otherwise wasn't used.

* Sandbox fixes

* Remove unused unit test package references.

Castle.Core and NUnit.ConsoleRunner.

* Update NUnit to 4.0.1

This requires replacing all the old assertion methods because they removed them 🥲

* Oh so that's what dotnet-eng was used for. Yeah ok that makes sense.

* Add Robust.Analyzers.Test

* Update submodule

* commit to re-run CI

Content.IntegrationTests/Tests/Buckle/BuckleTest.cs

@@ -111,7 +111,7 @@ namespace Content.IntegrationTests.Tests.Buckle
                     // Side effects of buckling for the strap
                     Assert.That(strap.BuckledEntities, Does.Contain(human));
                     Assert.That(strap.OccupiedSize, Is.EqualTo(buckle.Size));
-                    Assert.Positive(strap.OccupiedSize);
+                    Assert.That(strap.OccupiedSize, Is.Positive);
                 });
 
 #pragma warning disable NUnit2045 // Interdependent asserts.