Use __new__() for case counting

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
diff --git a/scripts/mbedtls_dev/test_generation.py b/scripts/mbedtls_dev/test_generation.py
index 59b3b08..9f4e296 100644
--- a/scripts/mbedtls_dev/test_generation.py
+++ b/scripts/mbedtls_dev/test_generation.py
@@ -51,8 +51,9 @@
     test_function = ""
     test_name = ""
 
-    def __init__(self) -> None:
-        type(self).count += 1
+    def __new__(cls, *args, **kwargs):
+        cls.count += 1
+        return super().__new__(cls)
 
     @abstractmethod
     def arguments(self) -> List[str]:
diff --git a/tests/scripts/generate_bignum_tests.py b/tests/scripts/generate_bignum_tests.py
index 1f64485..9551e21 100755
--- a/tests/scripts/generate_bignum_tests.py
+++ b/tests/scripts/generate_bignum_tests.py
@@ -92,8 +92,6 @@
     input_cases = [] # type: List[Tuple[str, ...]]
 
     def __init__(self, val_l: str, val_r: str) -> None:
-        super().__init__()
-
         self.arg_l = val_l
         self.arg_r = val_r
         self.int_l = hex_to_int(val_l)