graph: Set default BLOCK_CACHE_SIZE to i32::MAX

That makes it so that the new mechanism for setting the block cache size
has no effect by default

Author: lutter

graph/src/components/store/traits.rs

@@ -528,7 +528,7 @@ pub trait ChainIdStore: Send + Sync + 'static {
 /// The default size for the block cache, i.e., how many blocks behind
 /// the chain head we should keep in the database cache. The
 /// configuration can change this for individual chains
-pub const BLOCK_CACHE_SIZE: BlockNumber = 500;
+pub const BLOCK_CACHE_SIZE: BlockNumber = i32::MAX;
 
 /// Common trait for blockchain store implementations.
 #[async_trait]