fix(build): add rust and cargo dependency to builder image

fixes #1

Signed-off-by: SphericalKat <amolele@gmail.com>

.dockerignore

@@ -32,4 +32,7 @@ npm-debug.log
 # we ignore priv/static. You may want to comment
 # this depending on your deployment strategy.
 /priv/static/
-.idea
+.idea
+/native/ketbin_utils_syntax/target
+/native/ketbin_utils_syntax/.cargo
+.elixir_ls