drop unsused fstring in lexer.py (#21)

Author: Goodnight77

src/qql/lexer.py

@@ -213,7 +213,7 @@ def tokenize(self, query: str) -> list[Token]:
                     tokens.append(Token(TokenKind.NOT_EQUALS, "!=", i))
                     i += 2
                 else:
-                    raise QQLSyntaxError(f"Unexpected character '!'", i)
+                    raise QQLSyntaxError("Unexpected character '!'", i)
             elif ch == ">":
                 if i + 1 < n and query[i + 1] == "=":
                     tokens.append(Token(TokenKind.GTE, ">=", i))