Exclude translations folder from markdown validation workflow

[skytin1004]

🛠️ What’s Changed

This pull request updates the validate-markdown.yml workflow to exclude translation-specific directories from triggering markdown validation checks.

🔄 Changes

• Added paths-ignore rule to prevent triggering the workflow when only the following folders are modified:
  • translations/**
  • translated_images/**

✅ Why

These folders contain localized markdown and translated images that are frequently updated in bulk. Running validation jobs (e.g., broken link checks, path tracking) on them:

• Generates excessive noise
• Flags non-critical issues
• Slows down review cycles

By excluding these directories, we reduce false positives and streamline the PR validation process.

ℹ️ Note: Translated markdown files are regenerated by Co-op Translator whenever the original content changes.
This includes updated links, so there is no need to validate translated files manually.

[github-actions]

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