Skip test if torchvision is not available (#149494)

The test unconditionally imports torchvision and fails if the isn't installed.
Skip it in this case.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/149494
Approved by: https://github.com/janeyx99

test/inductor/test_benchmark_fusion.py

@@ -58,7 +58,10 @@ class BenchmarkFusionTestTemplate:
 
     @slowTest
     def test_resnet18(self):
-        import torchvision
+        try:
+            import torchvision
+        except ImportError:
+            self.skipTest("TorchVision not available")
 
         model = torchvision.models.resnet18()
         model.eval()