[PR #8833/26df6c76 backport][stable-9] use dict comprehension in plugins, part 3 (#8835)

use dict comprehension in plugins, part 3 (#8833)

* use dict comprehension in plugins, part 3

* add changelog frag

(cherry picked from commit 26df6c7657)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

plugins/cache/redis.py

@@ -227,7 +227,7 @@ class CacheModule(BaseCacheModule):
 
     def copy(self):
         # TODO: there is probably a better way to do this in redis
-        ret = dict([(k, self.get(k)) for k in self.keys()])
+        ret = {k: self.get(k) for k in self.keys()}
         return ret
 
     def __getstate__(self):