Update specialize.py

Author: BobTheBuidler

mypyc/irbuild/specialize.py

@@ -727,7 +727,7 @@ def get_literal_str(expr: Expression) -> str | None:
                 first = exprs[i]
                 concatenated = StrExpr(get_literal_str(first) + get_literal_str(exprs[i + 1]))  # type: ignore [operator]
                 exprs = [*exprs[:i], concatenated, *exprs[i + 2 :]]
-                format_ops = [*format_ops[:i], format_ops[i + 1], *format_ops[i + 2 :]]
+                format_ops = [*format_ops[:i], FormatOp.STR, *format_ops[i + 2 :]]
 
         substitutions = convert_format_expr_to_str(builder, format_ops, exprs, expr.line)
         if substitutions is None: