fix(rc2nix): correct regex for boolean values (#371)

Fix a regular expression in the `nix_val` function to correctly match and convert boolean values. The adjustment ensures that only exact matches for 'true' or 'false' are handled, preventing partial matches.

script/rc2nix.py

@@ -276,7 +276,7 @@ def pp_shortcuts(self, groups: Dict[str, Dict[str, str]], indent: int) -> str:
 def nix_val(s: Optional[str]) -> str:
     if s is None:
         return "null"
-    if re.match(r"^true|false$", s, re.IGNORECASE):
+    if re.match(r"^(true|false)$", s, re.IGNORECASE):
         return s.lower()
     if re.match(r"^[0-9]+(\.[0-9]+)?$", s):
         return s