MAINT: Remove silly mistake introduced with 0431f77

Author: PJBrs

pypdf/generic/_appearance_stream.py

@@ -392,9 +392,9 @@ def __init__(
 
         font_glyph_byte_map: dict[str, bytes]
         if isinstance(font.encoding, str):
-            font_glyph_byte_map = {}
-            for key, value in font.character_map.items():
-                font_glyph_byte_map[value] = key.encode(font.encoding)
+            font_glyph_byte_map = {
+                v: k.encode(font.encoding) for k, v in font.character_map.items()
+            }
         else:
             font_glyph_byte_map = {v: bytes((k,)) for k, v in font.encoding.items()}
             font_encoding_rev = {v: bytes((k,)) for k, v in font.encoding.items()}