Update required Java version to Java 17

[joshuasing]

Confirmation

• I have checked for similar issues.

Problem

The majority of platforms supported by Chameleon now require Java 17.
Additionally, Minecraft has required Java 17 since version 1.18 (released November 30, 2021).

Suggested solution

We should move to requiring Java 17 in Chameleon. We are already requiring Java 17 for building, as it is required by Paper, Sponge and soon Velocity (v3.3.0+).

As of May 3rd, 2024, data from bStats shows:

• 83.5% of all BungeeCord servers are using Java 17 or newer
• 87.3% of all Bukkit servers are using Java 17 or newer (and most servers are using Paper)
  Note: bStats is not enabled on all servers, so this data is an approximation.

A plugin built with Chameleon, UltraStaffChatPro has similar statistics with even more adoption for Java 17 or newer:

• 97.2% of BungeeCord servers using UltraStaffChatPro are using Java 17 or newer
• 98.9% of Velocity servers using UltraStaffChatPro are using Java 17 or newer (Velocity v3.3.0 will require Java 17)
• 92.4% of Bukkit servers using UltraStaffChatPro are using Java 17 or newer
  Note: bStats is not enabled on all servers, so this data is an approximation.

From this data, we believe that upgrading to Java 17 will not affect the majority of people using software built with Chameleon. Additionally, most of these servers can upgrade to using Java 17 (except some legacy servers).

There are many major improvements between Java 11 and Java 17 that would be useful for use in Chameleon development, and would allow us to improve many parts of Chameleon. Additionally, new Java APIs would be available for use.

Additional information

No response