Update build.yml

Update Java version in build flow

.github/workflows/build.yml

@@ -12,9 +12,7 @@ jobs:
       matrix:
         # Use these Java versions
         java: [
-          1.8,  # Minimum supported by Minecraft
-          11,   # Current Java LTS
-          15    # Latest version
+          16
         ]
         # and run on both Linux and Windows
         os: [ubuntu-20.04, windows-latest]