Fix potential SyntaxError when >= Python 3.12 (regex)

[alexander-beedie]

One of the regexes hadn't been set as a raw string; fixing that can avoid the following error on Python 3.12:

E       and not re.match(".*\[.*[dmhys].*\]", format_str)
E                        ^^^^^^^^^^^^^^^^^^^
E   SyntaxError: invalid escape sequence '\['

[ericpalakovichcarr]

@dilshod, thank you for all your work on this repo. Do you have any plans to create a new release with this change?

[dilshod]

@ericpalakovichcarr I just published 0.8.3 version.