ci: cover timestamp and Paraformer hotword regressions

[LauraGPT]

Summary

Keep the newly merged #3754 and #3761 regressions in the existing offline NumPy matrix, rather than relying on one-off maintainer validation.

• Add the timestamp splitter, both Paraformer hotword parser files, and their three test files to both pull_request and main-push path filters.
• Execute test_timestamp_tools.py, test_punc_model_none.py, and test_paraformer_hotword_file.py in the existing NumPy 1.26.4 / 2.4.0 job.
• Preserve CPU dependencies, read-only permissions, checkout source-SHA selection, offline mode, job timeout, and evidence uploads.

Validation

On current main 8f8931d plus this single-file patch, Linux/Python 3.12/CPU, no model weights:

• Structured YAML/command coverage checks: before 15 expected failures + 2 passes; after 17 passes.
• Parsed configuration comparison confirms the only changes are the intended path filters and pytest selection.
• Exact expanded workflow test selection, NumPy 1.26.4: 178 passed + 10 subtests passed, 3 existing warnings.
• Same selection, NumPy 2.4.0: 178 passed + 10 subtests passed, 75 existing warnings.
• Both JUnit files record 188 entries including subtests, zero failures/errors/skips.
• git diff --check and local SSH commit-signature verification pass.

No runtime implementation or dependency changes. A native actionlint binary is not installed; YAML structure and focused contract tests were checked, and the hosted workflow remains the promotion gate.

User Impact

Timestamp-tail and UTF-8/blank-line hotword regressions will automatically run for future relevant changes on both supported NumPy lanes. This does not claim real Windows, checkpoint inference, GPU, or model-accuracy validation.

Hosted Verification

Run 37736848377 completed successfully at exact head 1d7fc6e. Both NumPy artifacts record 188 JUnit entries including subtests, zero failures/errors/skips; all three added regression files are present. Artifact source-commit.txt matches the head in both lanes. This maintainer-owned PR uses the existing authorized administrator exemption after source, scope and hosted evidence checks; no independent review approval is claimed.