STY: Use f-strings (#2973)

Use f-strings in two methods of class PdfObject.

Author: j-t-1

pypdf/generic/_base.py

@@ -72,15 +72,12 @@ def hash_bin(self) -> int:
         )
 
     def hash_value_data(self) -> bytes:
-        return ("%s" % self).encode()
+        return f"{self}".encode()
 
     def hash_value(self) -> bytes:
         return (
-            "%s:%s"
-            % (
-                self.__class__.__name__,
-                self.hash_func(self.hash_value_data()).hexdigest(),
-            )
+            f"{self.__class__.__name__}:"
+            f"{self.hash_func(self.hash_value_data()).hexdigest()}"
         ).encode()
 
     def replicate(