[tests] fix `static` cache implementation is not compatible with...

[tests] fix `static` cache implementation is not compatible with `attn_implementation==flash_attention_2` (#32039)

* add flash attention check

* fix

* fix

tests/utils/test_cache_utils.py

@@ -290,7 +290,7 @@ class CacheIntegrationTest(unittest.TestCase):
         self.assertTrue(decoded[0].endswith(last_output))
 
     @require_torch_gpu
-    @parameterized.expand(["eager", "sdpa", "flash_attention_2"])
+    @parameterized.expand(["eager", "sdpa"])
     def test_static_cache_greedy_decoding_pad_left(self, attn_implementation):
         EXPECTED_GENERATION = [
             "The best color is the one that complements the skin tone of the",
@@ -330,7 +330,7 @@ class CacheIntegrationTest(unittest.TestCase):
             self.assertListEqual(decoded, EXPECTED_GENERATION)
 
     @require_torch_gpu
-    @parameterized.expand(["eager", "sdpa", "flash_attention_2"])
+    @parameterized.expand(["eager", "sdpa"])
     def test_static_cache_greedy_decoding_pad_right(self, attn_implementation):
         EXPECTED_GENERATION = [
             "The best color isЋ the one that complements the skin tone of",