Updated Upstream (Paper)

Upstream has released updates that appear to apply and compile correctly

Paper Changes:
PaperMC/Paper@39a1aa5c Promote build channel to stable

Author: granny

gradle.properties

@@ -2,8 +2,8 @@ group = org.purpurmc.purpur
 
 mcVersion = 26.1.2
 apiVersion = 26.1.2
-channel=EXPERIMENTAL
-paperCommit = 174eab0192cf7a56287330d422650f13e361e59f
+channel=STABLE
+paperCommit = 39a1aa5c7fa9742accf82c247a0ea18014788b5f
 
 org.gradle.configuration-cache = true
 org.gradle.caching = true