* [chore] Remove years from all license headers
Years or year ranges aren't required in license headers. Many projects
have removed them in recent years and it avoids a bit of yearly toil.
In many cases our copyright claim was also a bit dodgy since we added
the 2021-2023 header to files created after 2021 but you can't claim
copyright into the past that way.
* [chore] Add license header check
This ensures a license header is always added to any new file. This
avoids maintainers/reviewers needing to remember to check for and ask
for it in case a contribution doesn't include it.
* [chore] Add missing license headers
* [chore] Further updates to license header
* Use the more common // indentend comment format
* Remove the hack we had for the linter now that we use the // format
* Add SPDX license identifier
* fix incorrect static remote url use for emojis
* warn when emoji/attachment already exists
* defer emoji postdata execution
* rename ctx to innerCtx for clarity
* warn on emoji too large
* small efficiency fix in fetchRemoteAccountEmojis
* tidy up lock+load
* lock processing emojis
* fix little fucky wucky
* this wasn't go fmted for some reason
* select emoji using image_static_url
* use updated on AP emojis
* allow refetch of updated emojis
* cheeky workaround for test
* clean up old files for refreshed emoji
* check error for originalPostData
* shorten GetEmojiByStaticImageURL
* delete kirby (sorry nintendo)
* start implementing remote emoji fetcher
* update status where pk
* aaa
* tidy up a little
* check size limits for emojis
* thank you linter, i love you <3
* update swagger docs
* add emoji dereference test
* make emoji max sizes configurable
* normalize db.ErrAlreadyExists
