patch 8.2.2193: Vim9: can change constant in :def function

Problem:    Vim9: can change constant in :def function.
Solution:   Check if a variable is locked. (issue #7526)
diff --git a/src/version.c b/src/version.c
index 7c9529b..73a80aa 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2193,
+/**/
     2192,
 /**/
     2191,