job_queue: drop insert_unless_live, accept extra queue passes

mara chose to accept extra queued sweep passes over adding a new
hive-jobq primitive (or a hive-c0re one-off) for "don't queue another
of this kind". Every sweep caller now plain-inserts its node; the
capacity-1 Dep::Resource per sweep kind (MatrixSweep/KnowledgeTree)
still keeps two passes of the same kind from running concurrently, it
just no longer collapses a tick that lands while one is live or queued
into the existing one.

hive-c0re/src/job_queue/mod.rs

@@ -192,39 +192,6 @@ impl JobQueue {
         Ok(named)
     }
 
-    /// Insert the single node `declare` names, unless a node of `kind` is
-    /// already in one of the `fold_into` states. `None` means the caller's
-    /// request folded into that node and nothing was inserted.
-    ///
-    /// For a standalone sweep, where a pass that has not started yet already
-    /// covers "one more pass": it reads whatever is current when it runs. The
-    /// read and the insert share one lock, so two racing callers cannot both
-    /// miss the other.
-    ///
-    /// # Errors
-    /// Propagates a graph-insert error.
-    pub fn insert_unless_live(
-        &self,
-        kind: &NodeKind,
-        fold_into: &[State],
-        declare: impl FnOnce(&JobBuilder) -> Handle<'_>,
-    ) -> anyhow::Result<Option<NodeId>> {
-        let mut inner = self.lock();
-        let live = inner
-            .graph()
-            .nodes()
-            .any(|n| &n.payload == kind && fold_into.contains(&n.state));
-        if live {
-            return Ok(None);
-        }
-        let named = inner
-            .insert_job(None, |b| vec![declare(b).guid()])
-            .map_err(|e| anyhow::anyhow!("job_queue: graph insert failed: {e}"))?;
-        drop(inner);
-        self.notify.notify_one();
-        Ok(named.first().copied())
-    }
-
     /// The scheduler itself, for `hive_jobq`'s run-loop seam
     /// (`Scheduler::claim_next`), which takes exactly this type.
     ///