update yarn, loader and fabric

gradle.properties

@@ -4,14 +4,14 @@ org.gradle.jvmargs=-Xmx2G
 # check these on https://fabricmc.net/develop
 minecraft_base_version=1.20.2
 minecraft_version=1.20.2
-yarn_mappings=1.20.2+build.1
-loader_version=0.14.22
+yarn_mappings=1.20.2+build.4
+loader_version=0.15.0
 # Mod Properties
 mod_version=0.12.0-endec-alpha.13
 maven_group=io.wispforest
 archives_base_name=owo-lib
 # Dependencies
-fabric_version=0.89.2+1.20.2
+fabric_version=0.91.1+1.20.2
 
 # https://maven.shedaniel.me/me/shedaniel/RoughlyEnoughItems-fabric/
 rei_version=13.0.661