fix: add static modifiers to some Utils methods

src/main/java/cz/vsb/fei/efrei/lab03/Utils.java

@@ -17,10 +17,10 @@ public class Utils {
 			"Terrorclaw", "Bloodfeast", "Ravenous Maw", "Storm Serpent", "Hellhound", "Dark Overlord", "Necroshade",
 			"Plaguebeast", "Stone Golem", "Fire Leviathan");
 
-	public String generateHeroName() {
+	public static String generateHeroName() {
 		return heroNames.get(RANDOM.nextInt(heroNames.size()));
 	}
-	public String generateMonsterName() {
+	public static String generateMonsterName() {
 		return monsterNames.get(RANDOM.nextInt(monsterNames.size()));
 	}