Make regex strings raw strings

[StijnKas]

I was running into warnings on our regexes:

[/Users/kass1/Documents/pdstools/.venv/lib/python3.12/site-packages/pdstools/adm/ADMDatamart.py:1301](https://file+.vscode-resource.vscode-cdn.net/Users/kass1/Documents/pdstools/.venv/lib/python3.12/site-packages/pdstools/adm/ADMDatamart.py:1301): SyntaxWarning: invalid escape sequence '\-'
  return pl.col(x).str.replace_all("[ \-_]", "").str.to_uppercase()
[/Users/kass1/Documents/pdstools/.venv/lib/python3.12/site-packages/pdstools/pega_io/File.py:339](https://file+.vscode-resource.vscode-cdn.net/Users/kass1/Documents/pdstools/.venv/lib/python3.12/site-packages/pdstools/pega_io/File.py:339): SyntaxWarning: invalid escape sequence '\d'
  return fromPRPCDateTime(re.search("\d.*GMT", x)[0].replace("_", " "))

Fixed this by turning these strings into raw strings

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 59.59%. Comparing base (d6cc0c5) to head (5f1e122).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #232 +/- ## ======================================= Coverage 59.59% 59.59% ======================================= Files 29 29 Lines 3789 3789 ======================================= Hits 2258 2258 Misses 1531 1531 ```

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