Upgrade Gradle to v9.5 from v8.5

[Yang-33]

The current Gradle version is from two years ago. Let’s upgrade it to v9. The guide is here:
https://docs.gradle.org/current/userguide/upgrading_major_version_9.html

There were almost no difficult parts.

The main points are:

1. Some old plugin versions caused build failure because they do not support Gradle v9, so this change upgrades the plugin versions.
2. Test tasks now require stricter classpath and directory configuration. This affected the integration tests. To be safe, this change confirms that the number of executed tests after this change matches the current master branch, 215 unit tests + 41 itests.
   • https://docs.gradle.org/current/userguide/upgrading_major_version_9.html#test_tasks_may_no_longer_execute_expected_tests
3. junit-platform-launcher, which was previously used implicitly, now needs to be declared explicitly, so this change adds it.
   • https://docs.gradle.org/current/userguide/upgrading_version_8.html#test_framework_implementation_dependencies

A local publish comparison was also performed, confirming no major impact on the JARs.

[Yang-33]

The order here is important.

Since Gradle 8.14.4, accessing reserved configuration names derived from sourceSet before creating sourceSets has been deprecated. In Gradle 9, it becomes an error.

Without this change, the following error occurs:

Configuration with name 'itImplementation' not found.

[Yang-33]

eskatos/gradle-command-action has been moved to gradle/actions/setup-gradle finally.

• https://github.com/eskatos/gradle-command-action -> https://github.com/gradle/gradle-build-action -> https://github.com/gradle/actions/tree/main/setup-gradle

[Yang-33]

it's ready to be reviewed after #277 is merged into master branch~