make_key and make_pattern return None if key/pattern is None

(cherry picked from commit 409e95d)

Author: amirreza8002

django_valkey/util.py

@@ -30,17 +30,23 @@ def glob_escape(s: str) -> str:
 
 
 def make_key(
-    key: KeyT, key_func, version: int | None = None, prefix: str | None = None
-) -> str:
+    key: KeyT | None, key_func, version: int | None = None, prefix: str | None = None
+) -> CacheKey | None:
+    if not key:
+        return key
+
     if isinstance(key, CacheKey):
         return key
 
     return CacheKey(key_func(key, prefix, version))
 
 
 def make_pattern(
-    pattern: str, key_func, version: int | None = None, prefix: str | None = None
-) -> str:
+    pattern: str | None, key_func, version: int | None = None, prefix: str | None = None
+) -> CacheKey | None:
+    if not pattern:
+        return pattern
+
     if isinstance(pattern, CacheKey):
         return pattern