Fix Clippy lints (#3494)

* chore: fix some Clippy lints

* chore(labrinth): more Clippy fixes

packages/app-lib/src/api/pack/import/curseforge.rs

@@ -78,7 +78,7 @@ pub async fn import_curseforge(
         let icon_bytes =
             fetch(&thumbnail_url, None, &state.fetch_semaphore, &state.pool)
                 .await?;
-        let filename = thumbnail_url.rsplit('/').last();
+        let filename = thumbnail_url.rsplit('/').next_back();
         if let Some(filename) = filename {
             icon = Some(
                 write_cached_icon(

packages/app-lib/src/util/io.rs

@@ -139,9 +139,7 @@ pub async fn write(
         })
     })
     .await
-    .map_err(|_| {
-        std::io::Error::new(std::io::ErrorKind::Other, "background task failed")
-    })??;
+    .map_err(|_| std::io::Error::other("background task failed"))??;
 
     Ok(())
 }
@@ -152,8 +150,7 @@ fn sync_write(
 ) -> Result<(), std::io::Error> {
     let mut tempfile =
         NamedTempFile::new_in(path.as_ref().parent().ok_or_else(|| {
-            std::io::Error::new(
-                std::io::ErrorKind::Other,
+            std::io::Error::other(
                 "could not get parent directory for temporary file",
             )
         })?)?;