output: Fix permalink in sitemap etc. when multiple permalinkable output formats

output: Fix permalink in sitemap etc. when multiple permalinkable output formats

In Hugo 0.55.0 we made AMP `permalinkable`. We also render the output formats in their natural sort order, meaning `AMP` will be rendered before `HTML`. References in the sitemap would then point to the AMP version, and this is normally not what you'd want.

This commit fixes that by making `HTML` by default sort before the others.

If this is not you want, you can set `weight` on the output format configuration.

Fixes #5910