Clean up support for expression-based index INCLUDE

[khellang]

With the new generic IndexBuilder<TEntity> added in dotnet/efcore#14641, we should be able to add INCLUDE columns to an index using expressions.

[khellang]

Uh, I have no idea how I missed/forgot this, but it looks like I included this in #699 (see comment):

https://github.com/npgsql/Npgsql.EntityFrameworkCore.PostgreSQL/blob/e3421fa3e4d45546192069716bb94b77bf015a60/src/EFCore.PG/Extensions/NpgsqlIndexBuilderExtensions.cs#L81-L110

Just ignore this.

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One thing that we probably should do is follow the EF team and remove ForNpgsqlHasIndex and advise people to just use HasIndex (dotnet/efcore#14641).

Are we comfortable with removing the method directly, or should we delegate to HasIndex and put an ObsoleteAttribute on ForNpgsqlHasIndex for now?

[roji]

Uh, I have no idea how I missed/forgot this

That's the good kind of omission/forgetfulness 😆

Are we comfortable with removing the method directly, or should we delegate to HasIndex and put an ObsoleteAttribute on ForNpgsqlHasIndex for now?

I definitely think we should follow EF Core's lead on this one and remove it entirely (3.0 is a major version). Do you want to submit a PR for this?

[khellang]

Do you want to submit a PR for this?

Sure. I don't think we have any usages of this in the code base, so it'll be a remove-only PR 😊