I have a variable with some common values between dap-mode debug templates and I want to use that variable along with other cons elements for :environment-variable in languages like Golang or Typescript you would do something like this:

variable = [1, 2, 3]
another_variable = [...variable, 4, 5, 6]

then another_variable will carry the value of [1, 2, 3, 4, 5, 6]

How can I do this in Emacs Lisp?