Don't upgrade click to 8.x since click-repl doesn't support it yet.

Fixes celery#6511.
Upstream issue: click-contrib/click-repl#72

Author: Omer Katz

requirements/default.txt

@@ -2,7 +2,7 @@ pytz>dev
 billiard>=3.6.3.0,<4.0
 kombu>=5.0.0,<6.0
 vine>=5.0.0,<6.0
-click>=7.0
+click>=7.0,<8.0
 click-didyoumean>=0.0.3
 click-repl>=0.1.6
 click-plugins>=1.1.1