Add new CI scripts for building JAX artifacts
This commit introduces new CI scripts and environment files for building JAX artifacts. It makes use of the artifact envs inside the "ci/envs/build_artifacts" folder to control the build behavior. For e.g: for building jaxlib, we will need to run `./ci/build_artifacts.sh ./ci/envs/build_artifacts/jaxlib.env` from the JAX GitHub root.
PiperOrigin-RevId: 700104283
