Added Microsoft.Bcl.AsyncInterfaces to allow EventStore.gRPC to work on net6.0

[NielsPilgaard]

Added Microsoft.Bcl.AsyncInterfaces to allow EventStore.gRPC to work on net6.0

What this PR does / why we need it:
The 7.0.0 versions of EventStore gRPC do not work on net6.0 at the moment: #1692 (comment)

Which issue(s) this PR fixes:

Please reference the issue this PR will close: #[issue number]

Special notes for your reviewer:

Does this PR introduce a user-facing change?:
No

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Unit tests passing
• End-to-end tests passing
• Extended the documentation
• Provided sample for the feature

[NielsPilgaard]

Thanks 👍 Do you have an idea as to when you'll release this?

[sungam3r]

I can push preview ASAP if you want. As for release see #1593 (comment)

[NielsPilgaard]

Yes please, that'd be nice :)

[sungam3r]

https://github.com/Xabaril/AspNetCore.Diagnostics.HealthChecks/actions/runs/4308158958

[sungam3r]

Pushing AspNetCore.HealthChecks.EventStore.gRPC.7.0.0-rc2.4.nupkg to 'https://www.nuget.org/api/v2/package'...
  PUT https://www.nuget.org/api/v2/package/
warn : Readme missing. Go to https://aka.ms/nuget-include-readme learn How to include a readme file within the package.
  Created https://www.nuget.org/api/v2/package/ 912ms
Your package was pushed.

Wait 1-5 minutes because nuget needs to index package.

[NielsPilgaard]

AspNetCore.HealthChecks.EventStore.gRPC.7.0.0-rc2.4 does fix the issue 👍 thanks!