Preserve generated module map and response file mtimes for incremental builds

Warm tuist test –build-only invocations stay incremental again for projects whose Swift targets reference generated dependency module maps. Generated dependency module maps and response files keep stable mtimes between warm runs when their contents are unchanged, and stale generated files (*-deps.modulemap, *.resp) are still removed. This restores the warm-build performance regression introduced after 4.196.1.