Bug 1731223 - Wine is not optional on Windows cross-builds. r=firefox-build-system-reviewers,andi

Differential Revision: https://phabricator.services.mozilla.com/D125938

toolkit/moz.configure

@@ -2533,7 +2533,6 @@ def want_wine(target, host):
 wine = check_prog(
     "WINE",
     ["wine64", "wine"],
-    allow_missing=True,
     when=want_wine,
     bootstrap="wine/bin",
 )