Revert "Temporarily limit rustc commits"

This reverts commit 1a9cb03bd08c99bb9495b456d842fefe2f7b6ed7.

It seems that this was actually an upstream issue, so revert this commit for
now. We may need a fix here regardless, though.

src/db/rustc_commits.rs

@@ -27,7 +27,7 @@ pub async fn get_commits_with_artifacts(db: &DbClient) -> anyhow::Result<Vec<Com
         select sha, parent_sha, time
         from rustc_commits
         where time >= current_date - interval '168 days'
-        order by time desc limit 50;",
+        order by time desc;",
             &[],
         )
         .await