Don't call init reducer in spacetime generate (#4312)

# Description of Changes

Fixes #3492.

# Expected complexity level and risk

1

# Testing

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crates/core/src/host/host_controller.rs

@@ -338,8 +338,8 @@ impl HostController {
     ///
     /// This is not necessary during hotswap publishes,
     /// as the automigration planner and executor accomplish the same validity checks.
-    pub async fn check_module_validity(&self, database: Database, program: Program) -> anyhow::Result<Arc<ModuleInfo>> {
-        Host::try_init_in_memory_to_check(
+    pub async fn check_module_validity(&self, database: Database, program: Program) -> anyhow::Result<()> {
+        let (program, launched) = Host::try_init_in_memory_to_check(
             &self.runtimes,
             self.page_pool.clone(),
             database,
@@ -352,7 +352,14 @@ impl HostController {
             self.db_cores.take(),
             self.bsatn_rlb_pool.clone(),
         )
-        .await
+        .await?;
+
+        let call_result = launched.module_host.init_database(program).await?;
+        if let Some(call_result) = call_result {
+            Result::from(call_result)?;
+        }
+
+        Ok(())
     }
 
     /// Run a computation on the [`RelationalDB`] of a [`ModuleHost`] managed by
@@ -1012,8 +1019,7 @@ impl Host {
         })
     }
 
-    /// Construct an in-memory instance of `database` running `program`,
-    /// initialize it, then immediately destroy it.
+    /// Construct an in-memory instance of `database` running `program`.
     ///
     /// This is used during an initial, fresh publish operation
     /// in order to check the `program`'s validity as a module,
@@ -1029,7 +1035,7 @@ impl Host {
         program: Program,
         core: AllocatedJobCore,
         bsatn_rlb_pool: BsatnRowListBuilderPool,
-    ) -> anyhow::Result<Arc<ModuleInfo>> {
+    ) -> anyhow::Result<(Program, LaunchedModule)> {
         let (db, _connected_clients) = RelationalDB::open(
             database.database_identity,
             database.owner_identity,
@@ -1039,7 +1045,7 @@ impl Host {
             page_pool,
         )?;
 
-        let (program, launched) = launch_module(
+        launch_module(
             database,
             0,
             program,
@@ -1054,14 +1060,7 @@ impl Host {
             core,
             bsatn_rlb_pool,
         )
-        .await?;
-
-        let call_result = launched.module_host.init_database(program).await?;
-        if let Some(call_result) = call_result {
-            Result::from(call_result)?;
-        }
-
-        Ok(launched.module_host.info)
+        .await
     }
 
     /// Attempt to replace this [`Host`]'s [`ModuleHost`] with a new one running
@@ -1278,8 +1277,12 @@ pub(crate) async fn extract_schema_with_pools(
     };
 
     let core = AllocatedJobCore::default();
-    let module_info =
-        Host::try_init_in_memory_to_check(runtimes, page_pool, database, program, core, bsatn_rlb_pool).await?;
+    // Limit the scope of the launched module just to this block.
+    let module_info = {
+        let (_, launched) =
+            Host::try_init_in_memory_to_check(runtimes, page_pool, database, program, core, bsatn_rlb_pool).await?;
+        launched.module_host.info
+    };
     // this should always succeed, but sometimes it doesn't
     let module_def = match Arc::try_unwrap(module_info) {
         Ok(info) => Arc::try_unwrap(info.module_def).unwrap_or_else(|module_def| (*module_def).clone()),