Fix ServiceDescriptor access when Keyed Services are present

[ReubenBond]

Fix ServiceDescriptor access when Keyed Services are present

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Fixes the use of ServiceDescriptor for containers which have keyed services present. This can be an issue on .NET 8.0 and has been reported by some users of the library here: #2604

Description

The issue is caused by unconditional access to ServiceDescriptor.ImplementationType and the fix is to first check whether ServiceDescriptor.ServiceKey is set. If it is, we can safely ignore that descriptor.

For more information on keyed services, see the dotnet/runtime thread here: dotnet/runtime#64427 and the PR here: dotnet/runtime#87183.

Fixes #2604

[jmprieur]

Thanks @ReubenBond

LGTM

[adityamandaleeka]

Can this be merged now?

[onionhammer]

This seems like something that should be fixed sooner rather than later...

[jennyf19]

Thanks for the contribution @ReubenBond

[vijuhe]

Can this be released now or very soon at least? There is still one open feature in the release 2.17.1. Can the release be done without it?

[jennyf19]

@vijuhe we are testing the 2.17.1. It should be out later today PST.

[jennyf19]

Included in 2.17.1 Thanks @ReubenBond