unison: reduce closure size when enableX11 = false
Before: /nix/store/ifqr2nhgrci0ixga4k7pk9l6mqdfsk5b-unison-2.53.2 354.3MAfter: /nix/store/4cgr7fvqry0yrr8d76a5n0ykbm3wqx14-unison-2.53.2 40.9M
Henri Menke 2 years ago 1b94c25f e5f6200d