test: format gemm skip reason as markdown

Author: zkjh

tests/test_gemm.py

@@ -82,7 +82,7 @@ def test_gemm(
         and b_strides == (4096, 1)
         and c_strides == (4096, 1)
     ):
-        pytest.skip("Gemm impl=2 on Moore is unstable for padded strides")
+        pytest.skip("`Gemm` impl=2 on Moore is unstable for padded strides")
 
     a = randn_strided(a_shape, a_strides, dtype=dtype, device=device)
     b = randn_strided(b_shape, b_strides, dtype=dtype, device=device)