Migrate nullability annotations to jSpecify

Mojang has done that, we don't need 3 different sets of annotations

build.gradle

@@ -24,8 +24,6 @@ dependencies {
 	// Fabric API. This is technically optional, but you probably want it anyway.
 	//modImplementation "net.fabricmc:fabric:${project.fabric_version}"
 	//modCompileOnly fabricApi.module("fabric-rendering-v1", project.fabric_version)
-
-	compileOnly "com.google.code.findbugs:jsr305:${project.jsr305_version}"
 }
 
 processResources {