Remove runescape-api and mixins

This code is used by internal tooling to build the client patch, which
is already closed source, and is not directly shipped as a dependency.

Outside contributions to it are rare due to the lack of build tools, and it is
primarily being abused by others. As such, I no longer wish to release
further changes to it under BSD-2.

pom.xml

@@ -117,9 +117,7 @@
 		<module>cache-updater</module>
 		<module>runelite-api</module>
 		<module>runelite-client</module>
-		<module>runelite-mixins</module>
 		<module>runelite-script-assembler-plugin</module>
-		<module>runescape-api</module>
 		<module>http-api</module>
 		<module>http-service</module>
 		<module>protocol-api</module>