Fix concurrency issue about const apiUrl

[DL6ER]

What does this implement/fix?

Always use document.body.dataset.apiurl instead of the intermediate constant apiUrl

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Related issue or feature (if applicable): Fixes #3361 Fixes #3369

Pull request in docs with documentation (if applicable): N/A

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[DL6ER]

Sorry for the many force-pushes but I cannot run xo locally and I don't know why. It stays spinning the CPU at 100% for more than ten minutes until I manually kill it.

[XhmikosR]

Try removing your local node_modules folder and doing npm ci again. Also, check if you have the latest Node.js LTS on your system and maybe do npm cache clean -fg to clear the global npm cache.