[TEST] Fix test_topi_batch_matmul_tensorcore.py:test_batch_matmul req…

…uirement (#7294)

* this test current sets a requirement to "uses_gpu", which
   causes it to fail in cpu-only machine
 * this patch changes it to be "requires_tensorcore", as per discussion
   on issue #7277

tests/python/topi/python/test_topi_batch_matmul_tensorcore.py

@@ -63,7 +63,7 @@ def check_device(device):
     check_device("cuda")
 
 
-@tvm.testing.uses_gpu
+@tvm.testing.requires_tensorcore
 def test_batch_matmul():
     verify_batch_matmul(1, 1, 16, 16, 32)
     verify_batch_matmul(5, 5, 16, 16, 32)