Bump gradle version, and automate the upgrades

[trivikr]

Is your feature request related to a problem? Please describe.

The Gradle version was updated to 8.2.1 in Aug 2023 in #83

Since then, 15 more minor versions of gradle have been released: https://gradle.org/releases/
And the next major version is expected to be released in second quarter of 2025.

Describe the solution you'd like

• Manually bump gradle version to v8.13, and release a new minor/patch version of the plugin
• Set up GitHub Action to automatically update gradle version