fix: Handle ToolExceptions

What does this merge request do and why?

Fixes unhandled ToolExceptions by handling them in a similar way to the way that TypeErrors or ValidationErrors are handled in tools_executor.py.

How to set up and validate locally

1. Pull branch
2. Run a workflow that touches a forbidden file path (such as "Read the files in .git")
3. Workflow should not fail

Here's a couple of langsmith traces I ran locally [internal]:

• Chat workflow: link
• Software development workflow: link

Merge request checklist

• Tests added for new functionality. If not, please raise an issue to follow up.
• Documentation added/updated, if needed.
• If this change requires executor implementation: verified that issues/MRs exist for both Go executor and Node executor or confirmed that changes are backward-compatible and don't break existing executor functionality.

Closes #1333 (closed)