"util:new-language" doesn't create new end-to-end test files

[JoshuaKGoldberg]

What's going on?

I tried making a new supported source language:

npm run util:new-language -- --language-name PowerShell --language-extension .ps1 --base-name JavaScript --base-extension .js

Expected

Under each test/end-to-end/* directory, there should be a new directory for the language.

Actual

Error: ENOENT: no such file or directory, open 'C:\Code\budgie\test\end-to-end\Imports\Main.py'
    at Object.openSync (fs.js:454:3)
    at Object.readFileSync (fs.js:354:35)
    at C:\Code\budgie\util\createNewLanguage.js:56:39
    at Map.forEach (<anonymous>)
    at createLanguageTestsUnder (C:\Code\budgie\util\createNewLanguage.js:50:17)
    at createLanguageTests (C:\Code\budgie\util\createNewLanguage.js:62:5)
    at createNewLanguage (C:\Code\budgie\util\createNewLanguage.js:68:5)
    at main (C:\Code\budgie\util\createNewLanguage.js:105:5)
    at Object.<anonymous> (C:\Code\budgie\util\createNewLanguage.js:113:1)
    at Module._compile (internal/modules/cjs/loader.js:759:30)