Fix data map removals being required to exist (1.21.1 backport)

[62832]

Back-port of #1886 for MC 1.21.1. As per the original:

This PR fixes the oversight that makes data map removals required, erroring if they are not resolvable (such as being for an inexistent value). Removals should be optional.

[neoforged-pr-publishing]

• Publish PR to GitHub Packages

Last commit published: ffa1490646d80f46d8249071acf9157fa103f9dc.

PR Publishing

The artifacts published by this PR:

• 📦 net.neoforged:neoforge:21.1.101-pr-1889-fix-dmap-removals-backport
• 📦 net.neoforged:testframework:21.1.101-pr-1889-fix-dmap-removals-backport

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 #1889' // https://github.com/neoforged/NeoForge/pull/1889
        url 'https://prmaven.neoforged.net/NeoForge/pr1889'
        content {
            includeModule('net.neoforged', 'neoforge')
            includeModule('net.neoforged', 'testframework')
        }
    }
}

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-pr1889.
On Powershell you will need to remove the -L flag from the curl invocation.

mkdir NeoForge-pr1889
cd NeoForge-pr1889
curl -L https://prmaven.neoforged.net/NeoForge/pr1889/net/neoforged/neoforge/21.1.101-pr-1889-fix-dmap-removals-backport/mdk-pr1889.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.

[neoforged-releases]

🚀 This PR has been released as NeoForge version 21.1.104.