Use @azure-tools/cspell for spelling pin package name

[danieljurek]

The name cspell-version-pin was used to deliver malware (GHSA-pxjc-7552-fh9c). This uses a namespace over which we have control.

[Copilot]

Pull Request Overview

This PR updates the cspell package configuration to align with best practices for dependency management. The changes rename the package, mark it as private, and pin the cspell dependency to an exact version.

Key Changes:

• Package renamed from "cspell-version-pin" to "@azure-tools/cspell" with scoped naming
• Package marked as private to prevent accidental publication
• cspell dependency version changed from caret range (^9.2.1) to exact version (9.2.1)

[azure-sdk]

The following pipelines have been queued for testing:
java - template
java - template - tests
js - template
net - template
net - template - tests
python - template
python - template - tests
You can sign off on the approval gate to test the release stage of each pipeline.
See eng/common workflow

[azure-sdk]

The following pipelines have been queued for testing:
java - template
java - template - tests
js - template
net - template
net - template - tests
python - template
python - template - tests
You can sign off on the approval gate to test the release stage of each pipeline.
See eng/common workflow