Script: pass raw string as regex pattern

[Alex-Jordan]

My python version is 3.12.8. When I use the pretext script, I get these warnings:

/Users/alex.jordan/pretext/pretext/lib/pretext.py:2764: SyntaxWarning: invalid escape sequence '\['
  qtext = re.sub("\[\[validation:(\w+)\]\]", "", qtext)
/Users/alex.jordan/pretext/pretext/lib/pretext.py:2765: SyntaxWarning: invalid escape sequence '\['
  qtext = re.sub("\[\[feedback:(\w+)\]\]", "", qtext)
/Users/alex.jordan/pretext/pretext/lib/pretext.py:2768: SyntaxWarning: invalid escape sequence '\['
  ansids = re.findall("\[\[input:(\w+)\]\]", qtext)

The change here is so that a raw string, with literal backslash and literal bracket will be passed as the regex pattern. Then the regex itself will use the backslash to escape the bracket in pattern matching.