Only load resources once for gametest servers

[Matyrobbrt]

The current code would load resources twice for gametest servers due to the positioning of the code, causing needless slowdown. This PR moves the gametest server creation to just after pack repository creation and before resources are loaded in Main. Neither the GUI nor the server shutdown thread are necessary for gametest servers.

This PR also adds a test to make sure that reloadable regs support data maps (there were no code changes needed, this test is just to make sure it doesn't break in the future)

1.21.3 version of #1589

[neoforged-pr-publishing]

• Publish PR to GitHub Packages

Last commit published: 7b32f372a9132cfe9f32745a76de13cfa26660ca.

PR Publishing

The artifacts published by this PR:

• 📦 net.neoforged:testframework:21.3.8-beta-pr-1632-1213load-gametest-resources-once
• 📦 net.neoforged:neoforge:21.3.8-beta-pr-1632-1213load-gametest-resources-once

Repository Declaration

In order to use the artifacts published by the PR, add the following repository to your buildscript:

repositories {
    maven {
        name 'Maven for PR #1632' // https://github.com/neoforged/NeoForge/pull/1632
        url 'https://prmaven.neoforged.net/NeoForge/pr1632'
        content {
            includeModule('net.neoforged', 'testframework')
            includeModule('net.neoforged', 'neoforge')
        }
    }
}

MDK installation

In order to setup a MDK using the latest PR version, run the following commands in a terminal.
The script works on both *nix and Windows as long as you have the JDK bin folder on the path.
The script will clone the MDK in a folder named NeoForge-pr1632.
On Powershell you will need to remove the -L flag from the curl invocation.

mkdir NeoForge-pr1632
cd NeoForge-pr1632
curl -L https://prmaven.neoforged.net/NeoForge/pr1632/net/neoforged/neoforge/21.3.8-beta-pr-1632-1213load-gametest-resources-once/mdk-pr1632.zip -o mdk.zip
jar xf mdk.zip
rm mdk.zip || del mdk.zip

To test a production environment, you can download the installer from here.