graph: Avoid unwraps in blocks_with_subgraph_triggers

Author: incrypto32

graph/src/blockchain/block_stream.rs

@@ -338,7 +338,7 @@ impl<C: Blockchain> TriggersAdapterWrapper<C> {
         let store = self
             .source_subgraph_stores
             .get(&subgraph_filter.subgraph)
-            .unwrap(); // TODO(krishna): Avoid unwrap
+            .ok_or_else(|| anyhow!("Store not found for subgraph: {}", subgraph_filter.subgraph))?;
 
         let schema = crate::components::store::ReadStore::input_schema(store);