patch 8.2.2129: MS-Windows: Checking if a file name is absolute is slow

Problem:    MS-Windows: Checking if a file name is absolute is slow.
Solution:   Do not use mch_FullName(). (closes #7033)
diff --git a/src/version.c b/src/version.c
index 24a8390..9dae296 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2129,
+/**/
     2128,
 /**/
     2127,