JSON number handling breaking change

[gewarren]

Fixes #26771

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[IEvangelist]

I had one nit, otherwise looks good to me, when you're ready.

[IEvangelist]

Suggested change

A minor breaking change was introduced in .NET 6 with regard to the <xref:System.Text.Json.Serialization.JsonNumberHandlingAttribute> attribute. If you apply the attribute to a property that's a collection of non-number values and attempt to serialize or deserialize the property, an <xref:System.InvalidOperationException> is thrown. The attribute is only valid for properties that are collections of number types, for example:

A breaking change was introduced in .NET 6 with regard to the <xref:System.Text.Json.Serialization.JsonNumberHandlingAttribute> attribute. If you apply the attribute to a property that's a collection of non-number values and attempt to serialize or deserialize the property, an <xref:System.InvalidOperationException> is thrown. The attribute is only valid for properties that are collections of number types, for example:

I'm not sure it's a good idea to classify this as a "minor" breaking change. Any one who had code in place before that used this attribute in this way, would now experience an exception. It's still a breaking change, even though it may not affect as many consumers.