Update to 21w19a and Java 16

This commit can be used as an example on how to update your mod to Java 16. You will need to ensure you have Java 16 installed and set as the active version to run this.

Gradle 7 is required along with loom 0.8

src/main/resources/fabric.mod.json

@@ -27,9 +27,10 @@
   ],
 
   "depends": {
-    "fabricloader": ">=0.7.4",
+    "fabricloader": ">=0.11.3",
     "fabric": "*",
-    "minecraft": "1.16.x"
+    "minecraft": "1.17.x",
+    "java": ">=16"
   },
   "suggests": {
     "another-mod": "*"

src/main/resources/modid.mixins.json

@@ -2,7 +2,7 @@
   "required": true,
   "minVersion": "0.8",
   "package": "net.fabricmc.example.mixin",
-  "compatibilityLevel": "JAVA_8",
+  "compatibilityLevel": "JAVA_16",
   "mixins": [
   ],
   "client": [