patch 8.2.2346: Codecov reports every little coverage drop

Problem:    Codecov reports every little coverage drop.
Solution:   Tolerate a 0.05% drop. Hide the appveyor config file. (Ozaki
            Kiichi, closes #7678)

.codecov.yml

@@ -0,0 +1,6 @@
+coverage:
+  range: "80...100"
+  status:
+    project:
+      default:
+        threshold: 0.05%

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2346,
 /**/
     2345,
 /**/