Split out isrg from ssr and reorient build graph to make interpreter build 2x faster (#2969)

* split out isrg and core-types to speed up interpreter build

packages/ssr/src/lib.rs

@@ -4,8 +4,6 @@
 
 mod cache;
 pub mod config;
-#[cfg(feature = "incremental")]
-pub mod incremental;
 pub mod renderer;
 pub mod template;