Fix ruff check for strings/min_cost_string_conversion.py:143:39

Author: AryanJadhav15

strings/min_cost_string_conversion.py

@@ -140,7 +140,7 @@ def assemble_transformation(ops: list[list[str]], i: int, j: int) -> list[str]:
             elif op[0] == "R":
                 string[i] = op[2]
 
-                file.write("%-16s" % ("Replace %c" % op[1] + " with " + str(op[2])))
+                file.write(f"{'Replace ' + op[1] + ' with ' + str(op[2]):<16}")
                 file.write("\t\t" + "".join(string))
                 file.write("\r\n")