chore: bump Gradle to 8.1.1

[vlsi]

The PR upgrades to Gradle 8.1.1 and factors build logic to a set of files that compose together.
See https://docs.gradle.org/current/userguide/structuring_software_products.html

The end goal is to move the logic from /build.gradle.kts, and /src/build.gradle.kts to a coherent set of files in build-logic/

The current state is /build.gradle.kts 661 lines -> 153 lines, /src/build.gradle.kts 228 lines -> 0 lines (it no longer exists).

File layout

Imagine there's /src/core/build.gradle.kts that contains:

// in /src/core/build.gradle.kts
plugins {
    id("build-logic.jvm-published-library")
}

It means /src/core/build.gradle.kts applies all the bits from build-logic.jvm-published-library.gradle.kts.
If you open build-logic.jvm-published-library.gradle.kts, you'll see

// build-logic.jvm-published-library.gradle.kts
plugins {
    id("build-logic.jvm-library")
    id("build-logic.java-published-library")
}

Which means build-logic.jvm-published-library.gradle.kts composes build-logic.jvm-library.gradle.kts and build-logic.java-published-library.gradle.kts.

That means you can understand everything a given build.gradle.kts means by looking into plugins section and following the links.

Dependencies

Dependency versions are hard-coded within build.gradle.kts. It will enable adding Renovate bot for bumping the versions in the future.

TODO

• migrate jacoco
• migrate sonarqube
• add ApacheJMeter_bom (BOM for ApacheJmeter_* versions)
• add ApacheJMeter_thirdparty_bom (BOM with versions for third-party libraries)
• verify if the new build script works for "publish to Nexus". Sample staging repository: https://repository.apache.org/content/repositories/orgapachejmeter-1081/org/apache/jmeter/
• compare release artifacts with the ones produced by the previous build scripts

[FSchumacher]

Seems to work on my setup (using Java 8 with tasks, createDist and test and Java 20 with tasks and rungui)

[vlsi]

I think this is more-or-less ready. The missing bit is that the current checksum-dependency-plugin produces a lot of warnings:

Configure project :build-logic:basics
Multiple files present for artifact org.jetbrains.kotlin:kotlin-gradle-plugin-api:1.8.10: /Users/vlsi/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-gradle-plugin-api/1.8.10/71bb7a6e45dfa34ee566f88280c2b1d0514cb473/kotlin-gradle-plugin-api-1.8.10-gradle76.jar and /Users/vlsi/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-gradle-plugin-api/1.8.10/71bb7a6e45dfa34ee566f88280c2b1d0514cb473/kotlin-gradle-plugin-api-1.8.10.jar

[vlsi]

I've resolved the warnings, so I guess the PR is feature-complete.