chore: drop --pre-release rc from shipit

Now that 5.0.0 is stable, ShipIt should cut regular releases instead of
rc pre-releases.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dbrattli

justfile

@@ -79,7 +79,7 @@ release: pack
 
 # Run EasyBuild.ShipIt for release management
 shipit *args:
-    dotnet shipit --pre-release rc {{args}}
+    dotnet shipit {{args}}
 
 # Format code with Fantomas
 format: