Add update checker to notify about new versions (#22)

Checks GitHub releases API on startup and logs a message if a newer
version is available. The check runs asynchronously to avoid blocking
server startup.

Fix BungeeCord dependency resolution for CI builds (#21)

* Fix BungeeCord dependency resolution for CI builds

- Add includeTransitiveDeps parameter to provided() function
- Disable transitive deps for bungeecord-proxy (following Floodgate pattern)
- Use separate API and proxy dependency versions matching BungeeCord releases
- Fixes Sonatype SNAPSHOT repository resolution issues in CI

* Update PR workflow with correct naming and modern setup

- Rename artifact names from "Floodgate" to "Connect"
- Update actions/setup-java from v2 to v4
- Add gradle/actions/setup-gradle@v3
- Add fetch-depth: 0 for git describe versioning

Release version 0.7.0

- Fix BungeeCord LocalServerChannel compatibility via IoHandler delegation
- Fix Spigot/Paper handshake packet creation for Java 21 + modern versions
- Fix Velocity event loop integration with LocalSession
- Update Netty to 4.2.3.Final
- Add LocalSession.setPlatformEventLoopGroup() hook
- Implement ConnectIoHandlerWrapper for BungeeCord

Release version 0.7.0

- Fix BungeeCord LocalServerChannel compatibility via IoHandler delegation
- Fix Spigot/Paper handshake packet creation for Java 21 + modern versions
- Fix Velocity event loop integration with LocalSession
- Update Netty to 4.2.3.Final
- Add LocalSession.setPlatformEventLoopGroup() hook
- Implement ConnectIoHandlerWrapper for BungeeCord

Release version 0.7.0

- Fix BungeeCord LocalServerChannel compatibility via IoHandler delegation
- Fix Spigot/Paper handshake packet creation for Java 21 + modern versions
- Fix Velocity event loop integration with LocalSession
- Update Netty to 4.2.3.Final
- Add LocalSession.setPlatformEventLoopGroup() hook
- Implement ConnectIoHandlerWrapper for BungeeCord

Release version 0.6.2

Fixed bungeecord support that broke due to changes in bungeecord (#18)

* - Ported some changes from geyser/floodgate where they switched to the new [BungeeCord ChannelInitializer API](SpigotMC/BungeeCord#3776)
  - Updated the `bungeecord-proxy` dependency to 1.21.-R0.1-SNAPSHOT
  - Added a message when running an outdated bungeecord version (that doesn't support the new ChannelInitializer API)
  *Kept one and ported one funny comment*

  **Users are advised to upgrade their bungeecord proxies!**

* Updated the pullrequest workflow to use upload-artifact@v4 instead of the deprecated v2

* Forgot to delete an old util file that is no longer needed because of the BungeeCord ChannelInitializer API

* Removed an unused class related to skins that caused an error on Java 8

* Upgraded push request workflow to java 17

Support up to Minecraft 1.20.6

support Minecraft 1.20.2+

bump version to 0.4.0