chore: Add explicit permissions to PR linting workflow

[jperals]

Potential fix for https://github.com/cloudscape-design/chart-components/security/code-scanning/1

General Fix:
To address this, add a permissions block specifying only the least privileges required at either the workflow level (root, for all jobs) or, if some jobs need different permissions, inside the job(s) themselves. Since the only job in this file delegates to an external composite workflow, and without knowledge of any elevated permissions being required, the safest minimal starting point is to set permissions: read-all at the root of the workflow file (which gives all scopes read access only).

Detailed Fix:
Insert a permissions: block after the workflow's name: field and before on:, at the root level, with a value of read-all. This ensures that the workflow (and any called reusable workflow) receives only read-only access tokens by default, reducing the risk of unwanted repo modification. This is compliant with recommendations and does not otherwise affect workflow behavior.

Changes needed:

• Edit .github/workflows/lint-pr.yml
• Insert a block:

  permissions: read-all

  after line 1.
• No imports, methods, or other regions require editing or new dependencies.

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