perf: remove unnecessary contiguous operation in block sparse attention (#561)

The contiguous operation is no longer required after #513

Author: yzh119

python/flashinfer/sparse.py

@@ -435,9 +435,8 @@ def run(
             rope_scale = 1.0
         if rope_theta is None:
             rope_theta = 1e4
-
-        k = k.reshape(-1, self.C, *k.shape[-2:]).contiguous()
-        v = v.reshape(-1, self.C, *v.shape[-2:]).contiguous()
+        k = k.reshape(-1, self.C, *k.shape[-2:])
+        v = v.reshape(-1, self.C, *v.shape[-2:])
 
         lse = None
         if return_lse: