patch 9.0.1829: Vim9 missing access-checks for private vars

Problem:  Vim9 missing access-checks for private vars
Solution: Use the proper check for private/readonly variable.  Access
          level for a member cannot be changed in a class implementing an
          interface.  Update the code indentation

closes: #12978

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Co-authored-by: Ernie Rael <errael@raelity.com>

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1829,
 /**/
     1828,
 /**/