Replace `OrderedDictionary` from Microsoft.Experimental.Collections with the BCL type in .NET 9+

[alexrp]

novadrop/src/formats/formats.csproj

Lines 5 to 6 in 8e0d7f2

	<!-- TODO: Find a replacement for Microsoft.Collections.Extensions. -->
	<NoWarn>NU5104</NoWarn>

novadrop/src/formats/formats.csproj

Lines 23 to 25 in 8e0d7f2

	<ItemGroup>
	<PackageReference Include="Microsoft.Experimental.Collections" />
	</ItemGroup>

Blocked on:

• Switch minimum TFM to net10.0 #132

[alexrp]

Related:

• [API Proposal]: Add a generic OrderedDictionary class dotnet/runtime#24826
• [API Proposal]: LinkedDictionary dotnet/runtime#64829

[alexrp]

It may be worth considering simply not using an ordered dictionary here. When writing the data center file, attributes get sorted anyway. So, creating a data center in memory, writing it, and reading it back, the attributes will not have the same order as they did in memory during creation. It's not clear that using an ordered dictionary here actually adds much value.

Moving this for consideration in v2.0.