enable unreachable_pub lint

This causes some other lints to start firing too (which is good), but
I'm going to fix them in follow-up commits to keep things organized.

src/service/rooms/outlier.rs

@@ -1,28 +1,35 @@
 mod data;
 
-pub use data::Data;
+pub(crate) use data::Data;
 use ruma::{CanonicalJsonObject, EventId};
 
 use crate::{PduEvent, Result};
 
-pub struct Service {
-    pub db: &'static dyn Data,
+pub(crate) struct Service {
+    pub(crate) db: &'static dyn Data,
 }
 
 impl Service {
     /// Returns the pdu from the outlier tree.
-    pub fn get_outlier_pdu_json(&self, event_id: &EventId) -> Result<Option<CanonicalJsonObject>> {
+    pub(crate) fn get_outlier_pdu_json(
+        &self,
+        event_id: &EventId,
+    ) -> Result<Option<CanonicalJsonObject>> {
         self.db.get_outlier_pdu_json(event_id)
     }
 
     /// Returns the pdu from the outlier tree.
-    pub fn get_pdu_outlier(&self, event_id: &EventId) -> Result<Option<PduEvent>> {
+    pub(crate) fn get_pdu_outlier(&self, event_id: &EventId) -> Result<Option<PduEvent>> {
         self.db.get_outlier_pdu(event_id)
     }
 
     /// Append the PDU as an outlier.
     #[tracing::instrument(skip(self, pdu))]
-    pub fn add_pdu_outlier(&self, event_id: &EventId, pdu: &CanonicalJsonObject) -> Result<()> {
+    pub(crate) fn add_pdu_outlier(
+        &self,
+        event_id: &EventId,
+        pdu: &CanonicalJsonObject,
+    ) -> Result<()> {
         self.db.add_pdu_outlier(event_id, pdu)
     }
 }