KOMA-Script and long part numbers

I’m using KOMA-script (e.g. scrartcl) with polyglossia and the French language. Parts are therefore numbered like "Première partie", "Deuxième partie"…, instead of "Part I", "Part II"…

In English, KOMA-Script replaces "Part I" with just "I" in the table of contents, so the part number does not overlap the part title. But in French, this is for some reason not the case and the table of contents looks horrible. For example,

documentclass{scrartcl}
usepackage{polyglossia}
setmainlanguage{french}
begin{document}
tableofcontents
part{AAAAAA}
part{BBBBBB}
end{document}

gives this output:

How can I fix this? I tried to modify thepart but it does not seem to do anything; I even tried to put garbage (undefined commands) in it and the document still compiled fine so it’s apparently not even used… I also know that there is the toc=flat option, but this looks really bad in my opinion.

I am aware of this Q&A, but it deals with the memoir class and is not applicable here. As far as I can tell this is pretty much a bug in KOMA-Script, but since I am not able to read German I have no idea where to go on their website to report this so I’d settle for a quick and dirty fix.

documentclass{scrartcl}
usepackage{polyglossia}
setmainlanguage{french}
RedeclareSectionCommand[tocdynnumwidth=true]{part}
begin{document}
tableofcontents
part{AAAAAA}
part{BBBBBB}
end{document}