Drop sample from EF Core-Blazor article

[guardrex]

Fixes #34478

I'll drop the sample from the Blazor Samples repo on dotnet/blazor-samples#441 after this merges.

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Internal previews

📄 File	🔗 Preview link
aspnetcore/blazor/blazor-ef-core.md	aspnetcore/blazor/blazor-ef-core
aspnetcore/blazor/fundamentals/index.md	aspnetcore/blazor/fundamentals/index

[guardrex]

@adegeo (cc: @Rick-Anderson) ... We don't normally apply subsvc labels to PRs. Is this something new? If not, then there's a mini-😈 in the new label management process/code.

[adegeo]

It's not required. We do it in .NET docs to identify what area a PR touches. You want me to remove that?

[guardrex]

@Rick-Anderson ... Do you concur that we don't want the subsvc labels on the PRs, or is that useful to the team? Personally, I don't need them for anything.

[Rick-Anderson]

@Rick-Anderson ... Do you concur that we don't want the subsvc labels on the PRs, or is that useful to the team? Personally, I don't need them for anything.

I vote to nix them. We've got too many labels now.

[guardrex]

Ok, thx @Rick-Anderson.

@adegeo ... We only need the subsvc labels on issues.