Add cairo-test plugin to Scarb.toml manifest on new

scarb/src/ops/new.rs

@@ -9,6 +9,7 @@ use crate::internal::fsx;
 use crate::internal::restricted_names;
 use crate::subcommands::get_env_vars;
 use crate::{ops, DEFAULT_SOURCE_PATH, DEFAULT_TARGET_DIR_NAME, MANIFEST_FILE_NAME};
+use scarb_build_metadata::SCARB_VERSION;
 use std::process::{Command, Stdio};
 
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -152,6 +153,9 @@ fn mk(
             # See more keys and their definitions at https://docs.swmansion.com/scarb/docs/reference/manifest.html
 
             [dependencies]
+
+            [dev-dependencies]
+            cairo_test = "{SCARB_VERSION}"
         "#},
     )?;