Disable unused actix web features
Declare time feature for tokio
Update to actix-web 4
Update to edition 2021
Remove unused use
Update deps, use libc pledge/unveil
Remove .env.example and GH actions
Remove sqlite from CI runs
Revert "Revert "Add builds.sr.ht CI""

This reverts commit b7354b2075539e9e47b5dffd401265b08ee4ec49.

builds.sr.ht now has OpenBSD 6.9 support, so reenable this.
Use native html stuff to check input validity instead of bespoke js
Use atomic rename to write pastes
Fail immediately and noisily when failing to read the directory, so that admin will know to fix the file and it is not overwritten by an empty one
Implement publicity setting for files. It uses a query param to avoid mucking with multipart, which is a bit unfortunate since it doesn't match texts which use the post payload
Allow files/texts to be public or private. Still todo: UI update for files tab to expose public choice
Update package metadata
Fix missing pledges, also make bind address configurable
Pledge and unveil the app
Add some imports to clean code up and run clippy