Find invalid escape sequences (regular expression) in regular strings

[pfuntner]

In ae6d2d3 I fixed a problem in git-pulls where the script had a few regular strings with regular expression escape sequences. Since I had upgraded my system and was now using Python 3.12.3 (I'm not sure what I was using prior to the upgrade), the strings were generating warnings:

/home/mrbruno/bin/git-pulls:147: SyntaxWarning: invalid escape sequence '\s'

The solution is to do one of the following:

• turn the string into an r-string
• escaping backslashes

I would prefer not to find these piecemeal but I'm not sure how to find them otherwise. There may be an existing tool or I might have to write something.

[pfuntner]

I created find-invalid-escapes via 00419d0 and it seems to work well.