fix: use raw string for dashboard scope grammar

Use raw string (r-string) prefix for the dashboard scope grammar
string to prevent invalid escape sequence warnings for \- and \.
patterns in the regex.

This resolves SyntaxWarning issues in Python 3.13+ while maintaining
the same regex functionality. All existing tests pass.

Author: fuster92

sdcclient/monitor/dashboard_converters/_dashboard_scope.py

@@ -5,7 +5,7 @@ def convert_scope_string_to_expression(scope=None):
     if scope is None or not scope:
         return [True, []]
 
-    _SCOPE_GRAMMAR = """
+    _SCOPE_GRAMMAR = r"""
         @@grammar::CALC
 
         start = expression $ ;