feat: replace the old buggy 4JLibs with the community reimpl (https://github.com/smartcmd/4JLibs)

Minecraft.Client/Windows64/4JLibs/README.md

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+# Windows64 4JLibs
+
+This directory contains the Windows x64 `4JLibs` headers and libraries used by this project.
+
+Important: these files are based on the community reimplementation of `4JLibs`, not the original proprietary 4J Studios version.
+
+Source:
+
+- Community reimplementation: https://github.com/smartcmd/4JLibs
+
+In other words, the `inc/` and `libs/` contents here should be understood as the open community-maintained replacement that makes the Windows build possible, rather than a dump of the original upstream SDK/library package.