Add support for Paper 26.1, 26.2 and 26.3 - #291

Summary

This PR makes SkQuery build and run on the new Minecraft/Paper versioning scheme (26.x) and removes all Spigot-mapped internal reflection, which is no longer usable since Paper 26.1 dropped the internal remapper and ships unobfuscated server jars.

All existing SkQuery syntax stays the same: no script changes are required.

Motivation

• Minecraft changed its versioning to year.drop (26.1, 26.1.1, 26.2, 26.3, ...) and Minecraft/Paper 26.1+ requires Java 25.
• Paper 26.1 fully dropped the internal remapper. Plugins that reference Spigot-mapped internals (net.minecraft.server.<version>, org.bukkit.craftbukkit.<version>, PacketPlayOut*, obfuscated methods, etc.) no longer work, even through reflection.
• Skript 2.15+ is required for 26.x and is Paper-only.

Changes

Build

• build.gradle
  • Replaced org.spigotmc:spigot-api:1.21.11-R0.2-SNAPSHOT with io.papermc.paper:paper-api:26.1.2.build.74-stable (oldest target of the supported range).
  • Updated Skript from 2.14.3 to 2.16.2.
  • Added the PaperMC repository (https://repo.papermc.io/repository/maven-public/).
  • Removed the unused Spigot snapshots and BungeeCord oss.sonatype.org repositories.
  • Compilation stays on Java 21 bytecode so Paper 1.21.x can still remap/load the jar; building against the 26.x API itself requires JDK 25.
• gradle.properties
  • Version bumped from 4.3.1 to 4.4.0 (the 4.3.2 release tag never updated this file).
• .github/workflows/build.yml
  • CI build matrix updated from JDK 21 to JDK 25 (required to read paper-api 26.x class files).
  • Fixed the artifact-upload condition, which checked matrix.java == '17' and therefore never uploaded anything; it now checks '25'.

Plugin metadata

• src/main/resources/plugin.yml
  • api-version: 1.13 -> api-version: 1.21.4 (the minimum Minecraft version supported by Skript 2.16.2). This also opts the plugin into modern (1.20.5+) material behavior.

Removed Spigot-mapped internals

• EffShowCredits (display credits to %player%)
  • Removed the PacketPlayOutGameStateChange NMS packet construction and Reflection.sendPacket.
  • Now uses the public Paper API Player#showWinScreen() (available since Paper 1.19.x, verified in the 1.21.4 Javadocs).
• EffBlockFall (spawn [damaging] [undroppable] falling block ...)
  • Removed the org.bukkit.craftbukkit.<version>.entity.CraftFallingSand reflection and the obfuscated a(boolean) call.
  • Now uses FallingBlock#setHurtEntities(true).
  • Both old code paths only printed a stack trace when they failed, which they did on modern Paper, so these features now actually work instead of silently doing nothing.
• Reflection
  • Removed the now-unused NMS/OBC helpers: getNMSClass, getOBCClass, getHandle, getField, getMethod, classesEqual, sendPacket and getServerVersion (the latter also relied on the versioned CraftBukkit package that no longer exists).
  • Kept getCaller(), which is still used by Documentation.

Compatibility notes

• Works on Paper 1.21.4 through 26.3 with Skript 2.16.2.
• Spigot is no longer a target for these two elements because Player#showWinScreen() is Paper API. This is consistent with Skript 2.15+, which requires Paper.
• Servers older than 1.21.4 will refuse to load the plugin due to the new api-version.
• Skript 2.16.2 officially supports Paper up to 26.2; it also loaded without issues on 26.3 in testing.
• Existing scripts keep working unchanged; the syntax patterns were not modified.

Testing

• ./gradlew clean build with JDK 25 (Temurin 25.0.4) -> BUILD SUCCESSFUL.
• Compiled against Paper API 26.1.2.build.74-stable and also verified against 26.3 (alpha) with no compile errors.
• Booted real Paper servers with Skript 2.16.2 + the built jar and verified the plugin enables cleanly ([SkQuery] Enabling SkQuery v4.4.0, all 152 classes processed, no errors):
  • Paper 1.21.4 build 232 (remap succeeds with Java 21 bytecode)
  • Paper 26.1.2 build 74
  • Paper 26.2 build 129
  • Paper 26.3 build 133
• Also reviewed a production Paper 26.2 (build 129) log: SkQuery loads and enables without errors, and triggers no legacy-material warnings.