Include a warning about port spoofing in xml

[bseptember]

Include a warning about port spoofing in xml

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Summary of the changes

Added remark which describes the warning as per https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/health-checks?view=aspnetcore-7.0#require-host

Description

Update API remarks for RoutingEndpointConventionBuilderExtensions.RequireHost to warn about host spoofing

Fixes #48818 (documentation changed)

[amcasey]

Seems like something @captainsafia would have thoughts on.

Also, do we know why those crefs aren't binding?

[captainsafia]

@dotnet/aspnet-build CI status seems off on this PR. Can I get help merging since it's just a docs change?

[captainsafia]

@bseptember It looks like there is an XML syntax issue on the PR. Would you be able to fix it? Otherwise, I can make a modification in this branch.