Update GitHub Actions

[madmiraal]

Currently, the Rebel Engine GitHub workflows are raising warnings:

Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: .... For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.

The following actions uses node12 which is deprecated and will be forced to run on node16: actions/setup-java@v1. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/

The end-of-life date for Node.js 16 was brought forward by seven months to coincide with the end of support of OpenSSL 1.1.1 on 11th September 2023.[1]. This prompted GitHub to initiate the deprecation process for GitHub Actions using Node.js 16 and transition all actions to run on Node 20 by Spring 2024.[2].

This PR upgrades the GitHub workflow's actions to use the latest versions:

• actions/cache: v4
• actions/checkout: v4
• actions/setup-java: v4
• actions/setup-python: v5
• actions/upload-artifact: v4
• mymindstorm/setup-emsdk: v14

[1] https://nodejs.org/en/blog/announcements/nodejs16-eol/
[2] https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

[DanielaOrtner]

Thanks for being so proactive and keeping us in line with current version. :)