CI: release rockspec for Lua upon release

[f4z3r]

The following must be done for the LuaRocks publishing to work before publishing a new release on GH:

1. Rename the rockspec file to kcl_lib-<version>-1.rockspec.
2. Update package_version in the rockspec.

Right now the following would need to be done to ensure this can be published:

1. Create an account on https://luarocks.org/ (ideally called kcl-lang to represent the GH org).
2. Create an API key for that account.
3. Store the API key in this repository's secrets under the name LUAROCKS_API_KEY.

@Peefy I can create the account and generate the API key if you want and then send them to you somehow. However it probably makes more sense that you do this as I don't have permissions to update secrets in this repository and it makes sense that you control the kcl-lang account on LuaRocks IMO.

[f4z3r]

I currently only publish the rock as a source tar. This means that clients will still need to have a Rust toolchain installed when installing the rock. In the future we could also release a binary rock that already contains the dynamic library binary so that a Rust toolchain is not needed. However, this means that we would need to publish various versions of the rock for different OS/CPU architectures. I think for now this is fine as a source rock. I can create a ticket to change this to binary rocks for a future enhancement.

[Peefy]

LGTM. Thank you very much; I'll configure the API key a bit later.

[f4z3r]

@Peefy perfect, you can then publish the 0.12.4 version by simply locally running:

cd lua/
luarocks upload kcl_lib-0.12.4-1.rockspec --temp-key=<api-key>