Squash escape sequence warning in Python 3.12 build

[joefutrelle]

Getting this warning (not error) from the pip installation test for Python 3.12 (but not for earlier Python versions)

pyifcb/ifcb/data/identifiers.py:15: SyntaxWarning: invalid escape sequence '\.'

[joefutrelle]

This is quite confusing, because this is line 15

[johnwaalsh]

I noticed this too when using pyifcb with Python 3.12. I believe the line actually causing the issue is line 37:

pyifcb/ifcb/data/identifiers.py

Line 37 in 76e7c24

* ``\.`` - a regex dot (matches any character)

[joefutrelle]

Good catch. Eventually if we refactor this code the whole function can be replaced with something less over-engineered.