[libc++] Remove extraneous space in module.modulemap. NFC.

NOKEYCHECK=True
GitOrigin-RevId: 0444a0e8a9042a8dfb429086e5b7da09d4edfd44
diff --git a/include/module.modulemap b/include/module.modulemap
index 294abd4..9d196b9 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -1020,7 +1020,7 @@
       header "experimental/algorithm"
       export *
     }
-     module coroutine {
+    module coroutine {
       requires coroutines
       header "experimental/coroutine"
       export *