patch 8.2.1858: Vim9: filter functions return number instead of bool

Problem:    Vim9: filter functions return number instead of bool.
Solution:   Return v:true instead of one. (closes #7144)
diff --git a/src/popupwin.c b/src/popupwin.c
index 777e7d8..2868a9d 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -2375,7 +2375,8 @@
 	c = TO_SPECIAL(key[1], key[2]);
 
     // consume all keys until done
-    rettv->vval.v_number = 1;
+    rettv->v_type = VAR_BOOL;
+    rettv->vval.v_number = VVAL_TRUE;
     res.v_type = VAR_NUMBER;
 
     old_lnum = wp->w_cursor.lnum;
@@ -2429,7 +2430,8 @@
 	c = TO_SPECIAL(key[1], key[2]);
 
     // consume all keys until done
-    rettv->vval.v_number = 1;
+    rettv->v_type = VAR_BOOL;
+    rettv->vval.v_number = VVAL_TRUE;
 
     if (c == 'y' || c == 'Y')
 	res.vval.v_number = 1;