Fix some lint and typing issues uncovered by mypy/flake8 upgrades.

bemani/client/reflec/groovin.py

@@ -1,6 +1,6 @@
 import random
 import time
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, cast
 
 from bemani.client.base import BaseClient
 from bemani.protocol import Node
@@ -729,7 +729,7 @@ class ReflecBeatGroovinUpper(BaseClient):
                     'time': 54321,
                 },
             ],
-            key=lambda ep: ep['id'],
+            key=lambda ep: cast(int, ep['id']),
         )
         self.verify_player_rb4write(ref_id, location, episodes=dummyepisodes)
         episodes = sorted(

bemani/frontend/app.py

@@ -257,7 +257,7 @@ def navigation() -> Dict[str, Any]:
             'components': components,
             'any': jinja2_any,
         }
-    pages = []
+    pages: List[Dict[str, Any]] = []
 
     # Landing page
     pages.append(

bemani/utils/afputils.py

@@ -641,9 +641,9 @@ class AFPFile:
             vprint("Bit 0x000010 - regionmapping; NOT PRESENT")
 
         if feature_mask & 0x20:
-            vprint(f"Bit 0x000020 - text obfuscation on")
+            vprint("Bit 0x000020 - text obfuscation on")
         else:
-            vprint(f"Bit 0x000020 - text obfuscation off")
+            vprint("Bit 0x000020 - text obfuscation off")
 
         if feature_mask & 0x40:
             # Two unknown bytes, first is a length or a count. Secound is