Bring global variables into scope of include paths

[cdfa]

I would like globally declared variables to be in scope for expansion in include paths. I know something similar was requested in https://github.com/go-task/task/issues/670 and rejected, but I'm specifically asking for globally declared variables in the Taskfile, not environment variables.

For example, I would like to be able to abbreviate long paths with variables and use them in includes:

version: "3"

vars:
  LONG_PATH: some/very/loooooooooooooooooooong/path

includes:
  a: "{{.LONG_PATH}}/a"
  a: "{{.LONG_PATH}}/b"

I expected this kind of thing to work, because of the example with OS specific includes in the documentation, but OS is a different kind of variable, apparently. Would you consider adding this?