Remove unused TerminalStateChangeEvent
Remove unused TerminalStateChangeEvent

Fixes #131496

Microsoft/vscode,microsoft/vscode,microsoft/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,Microsoft/vscode,Microsoft/vscode,microsoft/vscode,microsoft/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,Microsoft/vscode,Microsoft/vscode,microsoft/vscode,Microsoft/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,Microsoft/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode,Microsoft/vscode,Microsoft/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,eamodio/vscode,eamodio/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,microsoft/vscode,microsoft/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode