[gpu] upgrade to PoCL v3.0 for building Linux integrated OpenCL wheels

[jameslamb]

Description

See #5252 (comment).

#5252 introduced the use of PoCL ("portable OpenCL") to build precompiled binaries of the Python package ("wheels") which allow switching to running on the GPU just by passing a runtime parameter, without the need to rebuild.

That PR used PoCL 1.8 (October 2021).

LightGBM should upgrade to using the newest version, v3.0 (June 2022).

Motivation

PoCL v1.8 only supports clang up to v13, whereas PoCL v3.0 supports clang v14.

Allows LightGBM to take advantage of another 8 months of performance improvements and bugfixes in PoCL.

How to do this

Note
This should only done by a LightGBM maintainer, on a LightGBM-official branch.

• complete [ci] [python-package] Use LightGBM-custom manylinux image for building aarch64 Linux wheels #5595
• switch to PoCL v3.0 in the manylinux2014_aarch64 image at https://github.com/guolinke/lightgbm-ci-docker/