upgrade orx-selfref-col dependency

Author: orxfun

Cargo.toml

@@ -16,7 +16,7 @@ orx-pinned-vec = { version = "3.21.0", default-features = false }
 orx-fixed-vec = { version = "3.22.0", default-features = false }
 orx-split-vec = { version = "3.22.0", default-features = false }
 orx-concurrent-iter = { version = "3.1.0", default-features = false }
-orx-selfref-col = { git = "https://github.com/orxfun/orx-selfref-col.git", branch = "make-NodeIdx-Send", default-features = false }
+orx-selfref-col = { version = "3.0.0", default-features = false }
 orx-parallel = { version = "3.3.0", default-features = false, optional = true }
 
 [dev-dependencies]