Use content-tag @ v4 features to avoid buffer math

[NullVoxPopuli]

nah, this doesn't work:

code.slice(template.range.startChar, template.range.endChar)
'<template>💩💩💩💩💩💩💩</te'

Now we have: embroider-build/content-tag#104

[evoactivity]

I think the updates fisker made to the preprocess script means we don't need this now?

[NullVoxPopuli]

yeah? noice