apply fix-multiple-type-scoped-contexts

[vamsikalagaturu]

Summary of changes

Fixes handling of multiple @type values in JSON-LD scoped contexts.
Previously, when a node had multiple types (e.g., {"@type": ["TypeA", "TypeB"]}), only the first matching type's scoped context was applied and all others were ignored. This caused incorrect JSON-LD processing when scoped contexts are spread across multiple types.
The fix:

• Merges scoped contexts from all matching types instead of stopping at the first match
• Iterates types in reverse order so earlier types in the list take priority (last-write-wins merge)
• Handles both dict and list context formats (@context can be either)

Checklist

• Checked that there aren't other open pull requests for
  the same change.
• Checked that all tests and type checking passes.
• If the change adds new features or changes the RDFLib public API:
  • Created an issue to discuss the change and get in-principle agreement.
  • Considered adding an example in ./examples.
• If the change has a potential impact on users of this project:
  • Added or updated tests that fail without the change.
  • Updated relevant documentation to avoid inaccuracies.
  • Considered adding additional documentation.
• Considered granting push permissions to the PR branch,
  so maintainers can fix minor issues and keep your PR up to date.