Fixed invalid escape sequences in string literals

[Lycan-Xx]

Fix invalid escape sequences in cupp.py

The script cupp.py contains several instances of invalid escape sequences, which are causing SyntaxWarnings to be raised. This PR addresses these issues by fixing the escape sequences.

The changes made are:

1. In line 161, the escape sequence \ has been replaced with \\.
2. In line 162, the escape sequence \ has been replaced with \\.
3. In line 164, the escape sequence \ has been replaced with \\.
4. In line 166, the escape sequence \ has been replaced with \\.

These changes should resolve the SyntaxWarnings and make the script more readable and maintainable.