Merge Hindi TN v2 from staging to main

[mgrafu]

What does this PR do ?

Add a one line overview of what this PR aims to accomplish.

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Pre checks:

• Have you signed your commits? Use git commit -s to sign.
• Do all unittests finish successfully before sending PR?
  1. pytest or (if your machine does not have GPU) pytest --cpu from the root folder (given you marked your test cases accordingly @pytest.mark.run_only_on('CPU')).
  2. Sparrowhawk tests bash tools/text_processing_deployment/export_grammars.sh --MODE=test ...
• If you are adding a new feature: Have you added test cases for both pytest and Sparrowhawk here.
• Have you added __init__.py for every folder and subfolder, including data folder which has .TSV files?
• Have you followed codeQL results and removed unused variables and imports (report is at the bottom of the PR in github review box) ?
• Have you added the correct license header Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. to all newly added Python files?
• If you copied nemo_text_processing/text_normalization/en/graph_utils.py your header's second line should be Copyright 2015 and onwards Google, Inc.. See an example here.
• Remove import guards (try import: ... except: ...) if not already done.
• If you added a new language or a new feature please update the NeMo documentation (lives in different repo).
• Have you added your language support to tools/text_processing_deployment/pynini_export.py.

PR Type:

• New Feature
• Bugfix
• Documentation
• Test

If you haven't finished some of the above items you can still open "Draft" PR.

In general, to fix an unused local variable that has no side effects, remove the variable assignment entirely. If the right‑hand side has important side effects, retain the expression (or its effects) and only remove or rename the unused variable. If the variable is intentionally unused for clarity, rename it to follow an “unused” convention.

Here, unit_graph_no_year is a pure composition of FSTs with no side effects and is never used. The best minimal fix is to delete the line that assigns unit_graph_no_year, leaving the preceding computation of unit_inputs_except_yr intact (since that variable might be used elsewhere, or we must not assume otherwise). Concretely, in nemo_text_processing/text_normalization/hi/taggers/measure.py, remove line 227 containing unit_graph_no_year = pynini.compose(...) and leave all other code unchanged. No new imports, methods, or definitions are required.

To fix the problem, remove the unused NEMO_CHAR name from the import statement while retaining the needed GraphFst import. This eliminates the unnecessary dependency without changing runtime behavior.

Concretely, in nemo_text_processing/text_normalization/hi/taggers/ordinal.py, on the line:

from nemo_text_processing.text_normalization.hi.graph_utils import NEMO_CHAR, GraphFst

we should remove NEMO_CHAR from the import list so that only GraphFst is imported. No other code changes are needed because NEMO_CHAR is not referenced anywhere in the shown code. This resolves the unused import warning without affecting existing functionality.