chore: fix TypeScript declarations lint errors (issue #11896)

[puneetdixit200]

Resolves #11896.

Description

This pull request:

• handles random lint runs where no TypeScript declaration files are selected, preventing grep under set -o pipefail from failing before the existing guard can skip linting.

Related Issues

This pull request has the following related issues:

• Fix TypeScript declarations lint errors #11896

Questions

No.

Other

Verification:

• Reproduced the existing no-match file selection failure with exit code 1.
• Verified the patched no-match case exits with code 0 and prints No TypeScript declaration files to lint.
• Verified a matching .d.ts file is still selected for linting.
• Ran git diff --check.

Checklist

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

I used AI assistance to inspect the workflow failure, reason about the shell behavior, and prepare the small workflow change. I reviewed the diff and verification before submission.

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@stdlib-js/reviewers