Newest Versions of MCreator have no more 1.12.2 Support

Issue description

Hi,

In your newest Snapshot have you the 1.15.2 Version added for newer Versions of Minecraft Forge. But I have on little question can you in the next Snapshot the 1.12.2 Version make back with the latest version. I play and Create so many mods and will with the newest Versions and Bugfixes what you make in all time Support for 1.12.2, 1.14.4 and 1.15.2 Mods make and find it not good what the 1.12.2 is not more integrated in the next versions.

Issue comments

We will have to drop support for Minecraft sooner than we expected. MCreator 2020.2 will be the last version to support Minecraft 1.12.2. The reason for this is that we will have to update to Java 8u252 which is unsupported by Minecraft 1.12.2, but not updating Java versions can cause security issues that we do not want. We will have to move to Java 9+ in the future too and this version is not supported by 1.12.2 and never will be, but we are missing out with features and performance improvements due to not updating Java to version higher than 8. More on incompatibility with Minecraft Forge <1.12.2 and Java updates above 8u242 can be read here: https://github.com/MinecraftForge/MinecraftForge/pull/6473

Cited from https://mcreator.net/news/57594/first-20202-snapshot-and-website-update.

bruh

Yes, the crash is indeed gone, but the pain of maintaining and testing all features on 3 generators is too much.

Imagine, I have to test each change I do in 3 different workspaces for 3 supported Forge versions. I just can't :/ And this number will just increase with new versions.

And all newer versions will be held back by features I wouldn't be able to add to keep compatibility with *very* limited code set of 1.12.2.