patch 8.2.4043: using int for second argument of ga_init2()

Problem:    Using int for second argument of ga_init2().
Solution:   Remove unnessary type cast (int) when using sizeof().
diff --git a/src/dict.c b/src/dict.c
index 64c9d5f..9c6b7d4 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -759,7 +759,7 @@
 
     if ((d = tv->vval.v_dict) == NULL)
 	return NULL;
-    ga_init2(&ga, (int)sizeof(char), 80);
+    ga_init2(&ga, sizeof(char), 80);
     ga_append(&ga, '{');
 
     todo = (int)d->dv_hashtab.ht_used;