patch 8.2.1457: Vim9: the output of :disassemble cannot be interrupted

Problem:    Vim9: the output of :disassemble cannot be interrupted.
Solution:   Check got_int. (closes #6715)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 0f7f18c3..424d42a 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -3182,6 +3182,11 @@
 			      break;
 	    case ISN_DROP: smsg("%4d DROP", current); break;
 	}
+
+	out_flush();	    // output one line at a time
+	ui_breakcheck();
+	if (got_int)
+	    break;
     }
 }