Make test fixture setup methods not be templated

This simplifies code slightly as nothing needs those functions to
be function templates.

Signed-off-by: Matthew Bentham <Matthew.Bentham@arm.com>
Change-Id: If48694bf5677bb83426aeba952eb87174a42dff0
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/c/VisualCompute/ComputeLibrary/+/536135
Tested-by: bsgcomp <bsgcomp@arm.com>
Reviewed-by: Jakub Sujak <jakub.sujak@arm.com>
Comments-Addressed: bsgcomp <bsgcomp@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9907
Benchmark: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/fixtures/CastFixture.h b/tests/validation/fixtures/CastFixture.h
index 056f664..60b4c2b 100644
--- a/tests/validation/fixtures/CastFixture.h
+++ b/tests/validation/fixtures/CastFixture.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2021 Arm Limited.
+ * Copyright (c) 2018-2021, 2023 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -36,7 +36,6 @@
 class CastValidationFixture : public framework::Fixture
 {
 public:
-    template <typename...>
     void setup(TensorShape shape, DataType dt_in, DataType dt_out, ConvertPolicy policy)
     {
         _target    = compute_target(shape, dt_in, dt_out, policy);