Improve environment variable handling and reading (#5389)

* wip: better env var reading

* move most env vars to env.rs

* migrate more env vars

* more migration

* more migrations

* More migration

* 🦀 dotenvy is gone (almost)

* 🦀 dotenvy is gone 🦀

* Fix mural source account env var handling

* Remove defaults from admin key vars

* dummy commit to update github pr

* fix ci

apps/labrinth/src/routes/v3/version_creation.rs

@@ -11,6 +11,7 @@ use crate::database::models::version_item::{
 };
 use crate::database::models::{self, DBOrganization, image_item};
 use crate::database::redis::RedisPool;
+use crate::env::ENV;
 use crate::file_hosting::{FileHost, FileHostPublicity};
 use crate::models::ids::{ImageId, ProjectId, VersionId};
 use crate::models::images::{Image, ImageContext};
@@ -974,7 +975,7 @@ pub async fn upload_file(
 
     version_files.push(VersionFileBuilder {
         filename: file_name.to_string(),
-        url: format!("{}/{file_path_encode}", dotenvy::var("CDN_URL")?),
+        url: format!("{}/{file_path_encode}", ENV.CDN_URL),
         hashes: vec![
             models::version_item::HashBuilder {
                 algorithm: "sha1".to_string(),