Upgrade Gradle to 7.5

[Fiouz]

• Upgrade Gradle from 7.0 to 7.5
• Update the existing unit test to test Gradle 7.5
• Also add GitHub Gradle Wrapper binary checking to avoid tampering

[VitaliyKulikov]

also, you can use in your readme file the way how to use git properties in a modern way)

version = project.provider{project.ext.gitProps['git.commit.id.abbrev']}

https://docs.gradle.org/current/javadoc/org/gradle/api/provider/Provider.html

[Fiouz]

also, you can use in your readme file the way how to use git properties in a modern way)

version = project.provider{project.ext.gitProps['git.commit.id.abbrev']}

https://docs.gradle.org/current/javadoc/org/gradle/api/provider/Provider.html

The scope of this PR is purposely limited to changing the version of the build tool, in order to facilitate code review.
As such, upgrading the project to modern Gradle idioms that were already missing before this PR (the Provider API has been around since Gradle 4) will not be done here (this can be done in a separate PR).