Not quite a scripting language, but I highly recommend you check out cosmo for your usecase. Cosmopolitan, and/or Actually Portable Executable (APE for short) is a project to compile a single binary in such a way that is is extremely portable, and that single binary can be copied across multiple operating systems and it will still just run. It supports, windows, linux, mac, and a few BSD’s.
https://cosmo.zip/pub/cosmos/bin/ — this is where you can download precompiled binaries of certain things using cosmo.
From my testing, the APE version of python works great, and is only 34 megabytes, + 12 kilobytes for the ape elf interpreter.
In addition to python, cosmopolitan also has precompiled binaries of:
And a few more, like tclsh, zsh, dash or emacs (53 MB), which I’m pretty sure can be used as an emacs lisp intepreter.
And it should be noted these may require the ape elf interpeter, which is 12 kilobytes, or the ape assimilate program, which is 476 kilobytes.
EDIT: It also looks like there is an APE version of perl, and the full executable is 24 MB.
EDIT again: I found even more APE/cosmo binaries:
OP is on OpenWRT (a router distro), and Alpine. Those distros don’t come with very much by default, and perl is not a core dependency for any of their default tools. Neither is python.
Based on the way the cosmo project has statically linked builds of python, but not perl, I’m guessing it’s more difficult to create a statically linked perl. This means that it’s more difficult to put perl on a system where it isn’t already there, and that system doesn’t have a package manager*, than python or other options.
*or the the user doesn’t want to use a package manager. OP said they just want to copy a binary around. Can you do that with perl?