Add spellcheck gha for docs

[ansermino]

Summary of changes

Changes introduced in this pull request:

• Copy over GHA from forest-docs-v2
• Add concurrency conditions and update triggers
• Disable caching due to known issue in setup-node, exact cause unknown

Reference issue to close (if applicable)

Part of #5045

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.