Revert test_flash_mla.py: restore watcher skip for Blackhole

The watcher skip for issue #37631 was prematurely removed. Restore it
until the underlying issue is fully resolved.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Pavle Josipovic

models/demos/deepseek_v3_b1/tests/unit_tests/test_flash_mla.py

@@ -12,7 +12,7 @@
 from loguru import logger
 
 import ttnn
-from models.common.utility_functions import comp_pcc
+from models.common.utility_functions import comp_pcc, is_blackhole, is_watcher_enabled
 from models.demos.deepseek_v3_b1.micro_ops.flash_mla.op import FlashMLADecode
 
 
@@ -22,6 +22,8 @@
 @pytest.mark.parametrize("max_seq_len", [32 * 1024])  # 32k max sequence length per chip
 def test_flash_mla_decode(device, batch_size, num_chunks, k_chunk_size, max_seq_len):
     """Test FlashMLADecode op."""
+    if is_blackhole() and is_watcher_enabled():
+        pytest.skip("Skipping test on Blackhole with watcher enabled, see issue #37631")
 
     # Calculate decode_position from num_chunks and k_chunk_size
     decode_position = num_chunks * k_chunk_size - 1