[braket] Add the symbol-dce pass to the lowering pipeline

[khalatepradnya]

This also fixes the following (non-fatal) error seen during 'observe' error: 'func.func' op Invalid number of binary-symplectic elements provided. Must provide 2 * NQubits = 0
(Ref: #2539)

• Manually ran the Braket test suite.

root@87c14fc11e0a:/workspaces/cuda-quantum/build# python3 -m pytest -rP ../python/tests/backends/test_braket.py
...                                                                                                                                   

../python/tests/backends/test_braket.py .......................                                                                                  [100%]

================================= PASSES =====================================
...
====================== 23 passed in 180.69s (0:03:00) ========================
{ 00:79 11:21 }
{ 00:25 01:19 10:26 11:30 }
{ 00:100 }
{ 0:53 1:47 }


root@87c14fc11e0a:/workspaces/cuda-quantum/build# bin/nvq++ --target braket ../docs/sphinx/targets/cpp/braket.cpp -o out.x && ./out.x
{ 00000:517 11111:483 }
{ 00000:494 11111:506 }

root@87c14fc11e0a:/workspaces/cuda-quantum/build# python3 ../docs/sphinx/targets/python/braket.py
{ 00:530 11:470 }

{ 00:507 11:493 }

[annagrin]

Thanks Pradnya!

[github-actions]

CUDA Quantum Docs Bot: A preview of the documentation can be found here.