Last-Modified date format is wrong

[janjhnsn]

Environment

Nitro v2.2.3 and node v16.14.2

Reproduction

Last-Modified uses mtime format which is ISO (2009-06-29T11:11:40Z) The documentation for Last-Modified states the format should be day-name, day month year hour:minute:second GMT or in other words UTC format.

Most browsers don't care about the format and sends the same formatted string as If-Modified-Since. Other systems (in our case Azure Frontdoor) validates the format and returns an error.

Describe the bug

Last-Modified is in the wrong format. I will submit a pull request for this.

Additional context

No response

Logs

No response