Update mixin to 0.8.4 (#366)

arclight-common/build.gradle

@@ -56,7 +56,7 @@ dependencies {
     implementation "org.spigotmc:spigot-api:$minecraftVersion-R0.1-SNAPSHOT@jar"
     implementation 'org.jetbrains:annotations:19.0.0'
 
-    implementation 'org.spongepowered:mixin:0.8.3'
+    implementation "org.spongepowered:mixin:$mixinVersion"
     annotationProcessor 'org.spongepowered:mixin:0.8.3:processor'
 
     implementation 'com.github.ArclightTeam:mixin-tools:1.0.0'

arclight-forge/build.gradle

@@ -40,7 +40,7 @@ repositories {
     maven { url = 'https://maven.izzel.io/releases' }
 }
 
-def embedLibs = ['org.spongepowered:mixin:0.8.3.2', 'org.yaml:snakeyaml:1.28',
+def embedLibs = ["org.spongepowered:mixin:$mixinVersion", 'org.yaml:snakeyaml:1.28',
                  'org.xerial:sqlite-jdbc:3.34.0', 'mysql:mysql-connector-java:5.1.49',
                  /*'commons-lang:commons-lang:2.6',*/ 'com.googlecode.json-simple:json-simple:1.1.1',
                  'org.apache.logging.log4j:log4j-jul:2.11.2', 'net.md-5:SpecialSource:1.10.0',

build.gradle

@@ -17,6 +17,7 @@ allprojects {
         forgeVersion = '37.0.44'
         apiVersion = '1.1.+'
         toolsVersion = '1.3.+'
+        mixinVersion = '0.8.4'
         gitHash = getGitHash()
     }