Update parse_eth_gas_report.py

Author: Doryu001

scripts/externalTests/parse_eth_gas_report.py

@@ -115,13 +115,11 @@ def to_json(self):
 
 
 def parse_bool(input_string: str) -> bool:
-    if input_string == 'true':
-        return True
-    elif input_string == 'false':
-        return True
-    else:
+    if input_string not in ('true', 'false'):
         raise ValueError(f"Invalid boolean value: '{input_string}'")
 
+    return input_string == 'true'
+
 
 def parse_optional_int(input_string: str, default: Optional[int] = None) -> Optional[int]:
     if input_string.strip() == '-':