Notebook read_cell_output tool reports "output is too big" for any output size

[oded-ist]

• Copilot Chat Extension Version: 0.45

Steps to Reproduce:

1. Open notebook with a code cell, any output will do, like "print(5+3)" - run it yourself, without the agent
2. Request the chat to read the output cell, it will report "output is too big"

The bug does not appear when the agent runs the cell itself, only when reading outputs of existing cells.

Pull request microsoft/vscode-copilot-chat#5093

[oded-ist]

Pull request #318148