Avoid shadowing built-in

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

Author: radarhere

src/PIL/FontFile.py

@@ -112,8 +112,8 @@ def compile(self) -> None:
 
     def _encode_metrics(self) -> bytes:
         values: tuple[int, ...] = ()
-        for id in range(256):
-            m = self.metrics[id]
+        for i in range(256):
+            m = self.metrics[i]
             if m:
                 values += m[0] + m[1] + m[2]
             else: