patch 8.2.2160: various typos

Problem:    Various typos.
Solution:   Fix spelling mistakes. (closes #7494)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 64b42cb..4fd62ce 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -3137,7 +3137,7 @@
 }
 
 /*
- * ":dissassemble".
+ * ":disassemble".
  * We don't really need this at runtime, but we do have tests that require it,
  * so always include this.
  */