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.MapRenderer/Content.MapRenderer.csproj

@@ -13,8 +13,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
+    <PackageReference Include="NUnit" />
+    <PackageReference Include="SixLabors.ImageSharp" />
   </ItemGroup>
 
   <Import Project="..\RobustToolbox\MSBuild\Robust.Properties.targets" />

Content.MapRenderer/Painters/EntityPainter.cs

@@ -115,7 +115,7 @@ public sealed class EntityPainter
             var (x, y, width, height) = GetRsiFrame(rsi, image, entity, layer, dir);
 
             var rect = new Rectangle(x, y, width, height);
-            if (!new Rectangle(Point.Empty, image.Size()).Contains(rect))
+            if (!new Rectangle(Point.Empty, image.Size).Contains(rect))
             {
                 Console.WriteLine($"Invalid layer {rsi!.Path}/{layer.RsiState.Name}.png for entity {_sEntityManager.ToPrettyString(entity.Owner)} at ({entity.X}, {entity.Y})");
                 return;