STY: Remove intermediate conversion to list (#3224)

Author: j-t-1

pypdf/_doc_common.py

@@ -1183,7 +1183,7 @@ def _flatten(
                             "Maximum recursion depth reached during page flattening."
                         )
         elif t == "/Page":
-            for attr_in, value in list(inherit.items()):
+            for attr_in, value in inherit.items():
                 # if the page has it's own value, it does not inherit the
                 # parent's value:
                 if attr_in not in pages:

pypdf/generic/_data_structures.py

@@ -511,7 +511,7 @@ def write_to_stream(
                 "the encryption_key parameter of write_to_stream", "5.0.0"
             )
         stream.write(b"<<\n")
-        for key, value in list(self.items()):
+        for key, value in self.items():
             if len(key) > 2 and key[1] == "%" and key[-1] == "%":
                 continue
             key.write_to_stream(stream, encryption_key)