Simplify Shadow 9.6 Kotlin DSL structure

[skrcode]

Purpose

This is a fork-only review PR against the branch used by upstream PR IntellectualSites#3639. It does not target the upstream repository.

What changed

• move relocation declarations onto the outer ShadowJar receiver;
• keep dependency inclusion and exclusion inside dependencies {};
• remove shadowJar and this@dependencies receiver qualifications;
• preserve all FAWE-specific relocations and dependency selections;
• retain the existing platformName and taskCoordinates captures.

The structure follows the approach used by EngineHub WorldEdit #3010.

Verification

• JDK 25: ./gradlew --no-daemon --max-workers=2 :build-logic:compileKotlin projects :worldedit-cli:shadowJar :worldedit-core:test :worldedit-bukkit:test :worldedit-cli:test — passed;
• git diff --check — passed;
• :worldedit-bukkit:shadowJar reaches adapter preparation but remains blocked before Shadow packaging by the existing Codebook 1.0.14 Unsupported class file major version 69 failure. The same configured Java 25 toolchain is selected when Gradle itself is launched with JDK 21.

Commit: signed off with Signed-off-by: Suraj Rajan <surajkrajan95@gmail.com>.

AI assistance

Prepared using JAIPilot workflow guidance:

• jaipilot-maintainer-intent
• jaipilot-fast-execution
• jaipilot-review-diff

Host model: gpt-5.6-sol
Reasoning effort: xhigh
Service mode: fast
Execution mode: local