Stop false duplicate xcframework warnings for SwiftPM convergence

Tuist generate no longer emits a false-positive “duplicate xcframework dependency” warning when the same binary SwiftPM target is reached through multiple external SwiftPM products. The mapping step now collapses identical .xcframework dependencies produced by .external expansion into a single graph dependency, so linting and generation agree on the same set of precompiled references. Hand-authored duplicate .xcframework entries in your manifest still trigger the warning, so genuine mistakes in your dependency list are still surfaced.