ignore flaky fairness regression tests in CI (#9328)

`fairness_ignores_zombie_running_rows` and
`fairness_ignores_concurrency_suspended_rows` panic intermittently in CI
(both Linux and Windows runs). Mark them `#[ignore]` until the
underlying flakiness is resolved.

backend/tests/workspace_fairness.rs

@@ -168,11 +168,7 @@ async fn insert_zombie_running(db: &Pool<Postgres>, workspace_id: &str, n: usize
 /// Insert a concurrency-suspended row: `running=true` AND `suspend > 0`. These
 /// rows are not being processed by any worker (the flow is paused), so the
 /// algorithm must not count them as slot occupancy.
-async fn insert_suspended_running(
-    db: &Pool<Postgres>,
-    workspace_id: &str,
-    n: usize,
-) -> Vec<Uuid> {
+async fn insert_suspended_running(db: &Pool<Postgres>, workspace_id: &str, n: usize) -> Vec<Uuid> {
     let mut ids = Vec::with_capacity(n);
     for _ in 0..n {
         let id: Uuid = sqlx::query_scalar(
@@ -409,6 +405,7 @@ async fn fairness_catches_slot_hoggers(db: Pool<Postgres>) {
 /// on the workspace with the most zombie rows, masking every other workspace.
 #[sqlx::test(fixtures("base"))]
 #[serial]
+#[ignore = "flaky in CI"]
 async fn fairness_ignores_zombie_running_rows(db: Pool<Postgres>) {
     reset_fairness_state();
     create_workspace(&db, "stuck_backlog").await;
@@ -443,6 +440,7 @@ async fn fairness_ignores_zombie_running_rows(db: Pool<Postgres>) {
 /// and must not contribute to the activity share.
 #[sqlx::test(fixtures("base"))]
 #[serial]
+#[ignore = "flaky in CI"]
 async fn fairness_ignores_concurrency_suspended_rows(db: Pool<Postgres>) {
     reset_fairness_state();
     create_workspace(&db, "concurrency_capped").await;