Add support for 1.21.5+ (Pale Garden generates more after 25w02a)

[Zes-MinKey-Young]

I was just doing the ShanHe CTF 3rd where there were MC-OSINT challenges and was happy to find this nice project. But in one challenge I found that the supporting version is not new enough.

Since I have no idea how to dump BTree data from IntelliJ IDEA, I have to use DataGenerator (i. e. java -cp "...;1.21.11.jar" net.minecraft.data.Main --report) to get the climate info, compare with the former versions and manually modify the binary BTree in tables/btree21wd.h. A very, very stupid mistake -- forgetting an else -- nearly drove me crazy, but I finally find it out...

By the way, Cubitect's strategy is "Development effort focuses on just the newest patch for each major release. Minor releases and major versions <= 1.0 are experimental." (See biomes.h) I personally think that this is gradually becoming questionable, since Mojang are turning into an era where big themes are breaking into many small updates.

It is my first time to contribute to a C library project. If I did something wrongly, please feel free to point it out, thanks.

[xpple]

I think it makes more sense to call the table btree215.h, as that was the version that introduced the change.

The iffs in the comments are not typos, they are mathematical abbreviations for "if and only if".

I am pretty sure you need to add a new biome parameter range entry here as well.

You added MC_1_21_11 but you didn't update MC_NEWEST.

Lastly, you are right that the versioning strategy for Cubiomes is a bit outdated. I believe Cubitect has also said this.