Fix incorrect indentation

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
diff --git a/tests/scripts/generate_bignum_tests.py b/tests/scripts/generate_bignum_tests.py
index 299b619..61f642b 100755
--- a/tests/scripts/generate_bignum_tests.py
+++ b/tests/scripts/generate_bignum_tests.py
@@ -156,7 +156,7 @@
     def get_value_pairs(cls) -> Iterator[Tuple[str, ...]]:
         """Generate value pairs."""
         for pair in list(
-            itertools.combinations(cls.input_vals, 2)
+                itertools.combinations(cls.input_vals, 2)
             ) + cls.input_cases:
             yield pair