Ignore shutdown pty host messages when already shutdown
Ignore shutdown pty host messages when already shutdown

Fixes #120010
Fixes #119989

Krzysztof-Cieslak/vscode,microsoft/vscode,Microsoft/vscode,eamodio/vscode,Microsoft/vscode,Microsoft/vscode,Krzysztof-Cieslak/vscode,Krzysztof-Cieslak/vscode,Microsoft/vscode,Microsoft/vscode,Krzysztof-Cieslak/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,Krzysztof-Cieslak/vscode,eamodio/vscode,Krzysztof-Cieslak/vscode,microsoft/vscode,Microsoft/vscode,eamodio/vscode,microsoft/vscode,Microsoft/vscode,Krzysztof-Cieslak/vscode,Microsoft/vscode,Microsoft/vscode,microsoft/vscode,Krzysztof-Cieslak/vscode,Microsoft/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,Microsoft/vscode,microsoft/vscode,Krzysztof-Cieslak/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,Krzysztof-Cieslak/vscode,eamodio/vscode,Krzysztof-Cieslak/vscode,eamodio/vscode,Krzysztof-Cieslak/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,Krzysztof-Cieslak/vscode,Krzysztof-Cieslak/vscode,Krzysztof-Cieslak/vscode,Microsoft/vscode,Krzysztof-Cieslak/vscode,Krzysztof-Cieslak/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,microsoft/vscode