Listener Leak -- CodeCell output menu related

[Yoyokrazy]

got one recently

  ERR [169] potential listener LEAK detected, having 177 listeners already. MOST frequent listener (2):: Error
    at Stacktrace.create (vscode-file://vscode-app/d:/src/vscode/out/vs/base/common/event.js:730:21)
    at PersistedMenuHideState._event [as onDidChange] (vscode-file://vscode-app/d:/src/vscode/out/vs/base/common/event.js:865:46)
    at Object.startLazyListener [as onWillAddFirstListener] (vscode-file://vscode-app/d:/src/vscode/out/vs/platform/actions/common/menuService.js:379:43)
    at MenuImpl._event [as onDidChange] (vscode-file://vscode-app/d:/src/vscode/out/vs/base/common/event.js:872:56)
    at CellOutputElement._attachToolbar (vscode-file://vscode-app/d:/src/vscode/out/vs/workbench/contrib/notebook/browser/view/cellParts/cellOutput.js:284:42)
    at CellOutputElement.render (vscode-file://vscode-app/d:/src/vscode/out/vs/workbench/contrib/notebook/browser/view/cellParts/cellOutput.js:172:18)
    at CellOutputContainer._doRender (vscode-file://vscode-app/d:/src/vscode/out/vs/workbench/contrib/notebook/browser/view/cellParts/cellOutput.js:483:23)
    at CellOutputContainer.render (vscode-file://vscode-app/d:/src/vscode/out/vs/workbench/contrib/notebook/browser/view/cellParts/cellOutput.js:460:18)
    at new CodeCell (vscode-file://vscode-app/d:/src/vscode/out/vs/workbench/contrib/notebook/browser/view/cellParts/codeCell.js:96:39)
    at InstantiationService._createInstance (vscode-file://vscode-app/d:/src/vscode/out/vs/platform/instantiation/common/instantiationService.js:130:24)

Originally posted by @amunger in #211112