Upgrade to Rocket v0.5.2 (#7890)

Upgrade Rocket to v0.5.2 which has updated all the crate dependencies.
Also adjusted some code which I changed with Rkt and during that found
some small bugs and fixed those too.

Adjusted the ETag Caching a bit.

Also updated other crates and GHA.

Signed-off-by: BlackDex <black.dex@gmail.com>

src/api/mod.rs

@@ -30,7 +30,7 @@ pub use crate::api::{
     },
     web::catchers as web_catchers,
     web::routes as web_routes,
-    web::{invalidate_css_cache, static_files},
+    web::{STATIC_FILES, invalidate_css_cache},
 };
 use crate::{
     CONFIG,