Enable RollForward to run on the latest .NET SDKs

[nil4]

Enables installing and running CycloneDX on runtimes/SDKs newer than those that it targets when published. (For instance, allows v4.0.0 to run with only .NET SDK 9.0 installed, and no 8.0, 7.0 or 6.0 present.)

ref. https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-core-3-0#major-version-runtime-roll-forward
ref. dotnet/sdk#26824

Examples of other tools which have this setting enabled:

• dotnet-format (MS): https://github.com/dotnet/format/blob/ad8125a6fc036fe1eb4e57aa604a79f2d98d5aa0/src/dotnet-format.csproj#L11 -- added in dotnet/format@7a5df81
• dotnet-ef (MS): https://github.com/dotnet/efcore/blob/486047c7422ec04530ca66c7c55256fa89b0ffc2/src/dotnet-ef/dotnet-ef.csproj#L24 -- added in dotnet/efcore@11e7fc6
• docfx (MS): https://github.com/dotnet/docfx/blob/dbd57048f68411fa39aeea9ccc6c00dc88ecde9f/src/docfx/docfx.csproj#L5 -- added in dotnet/docfx@c641c03
• my own dotnet-xdt: https://github.com/nil4/dotnet-transform-xdt/blob/6272bb1152e8535ec40da5b0d68ff950bc13735b/dotnet-xdt/dotnet-xdt.csproj#L47 -- added in Run with only .NET Core 3.x installed nil4/dotnet-transform-xdt#42

[mtsfoni]

I like it. Are there any potential downsides?
Breaking changes in the runtime I'd guess, but those are usually rare and very specific.

[nil4]

Nothing specific that I'm aware of.

In the linked issue I gave some examples of other Microsoft-published tools (e.g. dotnet-format and docfx) having this set for a while now with no apparent downside.

One of the tools I published earlier (dotnet-xdt) also had it enabled for some years without any issues.