refactor: TechStackName enum 대문자 수정

Author: jaehyeon4406

src/main/java/com/devpath/domain/user/enums/TechStackName.java

@@ -6,10 +6,10 @@
 public enum TechStackName {
 
     REACT("React"),
-    VUE("Vue.js"),
-    NextJS("Next.js"),
-    TypeScript("TypeScript"),
-    Flutter("Flutter"),
+    VUEJS("Vue.js"),
+    NEXTJS("Next.js"),
+    TYPESCRIPT("TypeScript"),
+    FLUTTER("Flutter"),
 
     JAVA("Java"),
     SPRING("Spring"),