[API](feat) Deprecate legacy sync block APIs

[Misaka19280hw]

Why

The legacy triton.language.sync_block_all, sync_block_set, and sync_block_wait wrappers still use ad-hoc DeprecationWarning calls. Standardize their sunset behavior with the _deprecated mechanism introduced for main-dev, and point users to the public Ascend extension APIs.

What

• Decorate the three legacy wrappers with _deprecated.
• Use the full triton.language.extra.cann.extension.sync_block_* replacement paths.
• Remove the old inline warning code without changing the synchronization bodies.
• Add backend-independent tests for the warning message, builtin marker, and builder argument forwarding.

Validation

• pre-commit run --from-ref origin/main-dev --to-ref HEAD
• git diff origin/main-dev..HEAD --check
• python -m pytest --collect-only -q third_party/ascend/unittest/pytest_ut/test_aux_ops_deprecation.py (3 tests collected)
• Source-level checks verified the three decorator arguments and removal of the inline warnings.
• The tests were not executed against the locally installed wheel because it predates the current _semantic protocol; CI builds and installs the current checkout before running pytest_ut.

New contributor declaration

• I am not making a trivial change, such as fixing a typo in a comment.
• I have written a PR description following these rules.
• I have run pre-commit run --from-ref origin/main-dev --to-ref HEAD.
• I have added Python tests under third_party/ascend/unittest/pytest_ut.
• I have not added any lit tests.