Nuke.Common can't compile after `nuke :setup` — mirrors upstream #1588

[ChrisonSimtian]

Mirror of nuke-build/nuke#1588. .NET 10 follow-up bug — first-run nuke :setup produces a build that fails to compile.

[ChrisonSimtian]

Moved to v11 alongside #45 — same breaking release that formalises the in-support-only .NET target policy.

Two follow-ups needed when this gets picked up:

• Title still uses nuke :setup — current tool is dotnet fallout (or fallout global tool). Rename the title once the actual command name in the current code is confirmed.
• Reverify the bug reproduces against current Fallout setup tooling (not against legacy NUKE). The upstream mirror is from May 2026 and the codebase has moved since.