patch 8.2.3579: CI sometimes fails for MinGW

Problem:    CI sometimes fails for MinGW.
Solution:   Use backslashes in HandleSwapExists(). (Christian Brabandt,
            closes #9078)
diff --git a/src/version.c b/src/version.c
index 9c0f845..2dd061e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3579,
+/**/
     3578,
 /**/
     3577,