[CustomTextEditor extensions] A second duplicate editor tab opens when doing "Reopen with... Cat Scratch" on **untitled** file, then making any change using the custom editor

<!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- 🕮 Read our guide about submitting issues: https://github.com/microsoft/vscode/wiki/Submitting-Bugs-and-Suggestions --> <!-- 🔎 Search existing issues to avoid creating duplicates. --> <!-- 🧪 Test using the latest Insiders build to see if your issue has already been fixed: https://code.visualstudio.com/insiders/ --> <!-- 💡 Instead of creating your report here, use 'Report Issue' from the 'Help' menu in VS Code to pre-fill useful information. --> <!-- 🔧 Launch with `code --disable-extensions` to check. --> Does this issue occur when all extensions are disabled?: Yes/No <!-- 🪓 If you answered No above, use 'Help: Start Extension Bisect' from Command Palette to try to identify the cause. --> <!-- 📣 Issues caused by an extension need to be reported directly to the extension publisher. The 'Help > Report Issue' dialog can assist with this. --> - VS Code Version: 1.67.2 - OS Version: Windows 10 When doing "Reopen with... Cat Scratch" on **untitled** file, when making any change using the custom editor, an additional new tab opens with the same document, but using the default text editor. Steps to Reproduce: 1. Open the https://github.com/microsoft/vscode-extension-samples/tree/0d36653b0da5041f49fe049e34f6d8671f8e1002/custom-editor-sample 3. Press F5 to debug the extension. 4. Double-click on the tab bar to open new "Untitled 1" tab. 6. Use "Reopen with..." / "Cat Scratch" on the "Untitled 1" file. 10. Click the "Add scratch' button. 11. A new 2nd tab opens with the "Untitled 1", but with the default text editor showing the JSON CatScratch data. That tab remains in sync with the custom editor tab. I expect editing custom document to not result in spontaneously opening the default text editor. https://user-images.githubusercontent.com/1829149/169727649-f22a7ae9-a680-49fa-a0b2-1a1310485be0.mp4