Apply ruff/flake8-implicit-str-concat rule ISC003

Explicitly concatenated string should be implicitly concatenated

Author: DimitriPapadopoulos

tabulate/__init__.py

@@ -304,7 +304,7 @@ def make_header_line(is_header, colwidths, colaligns):
     else:
         raise ValueError(
             "_asciidoc_row() requires two (colwidths, colaligns) "
-            + "or three (cell_values, colwidths, colaligns) arguments) "
+             "or three (cell_values, colwidths, colaligns) arguments) "
         )
 
 
@@ -1413,7 +1413,7 @@ def _prepend_row_index(rows, index):
     if isinstance(index, Sized) and len(index) != len(rows):
         raise ValueError(
             "index must be as long as the number of data rows: "
-            + f"len(index)={len(index)} len(rows)={len(rows)}"
+             f"len(index)={len(index)} len(rows)={len(rows)}"
         )
     sans_rows, separating_lines = _remove_separating_lines(rows)
     new_rows = []