[feat] Vendor 생성은 비밀번호를 8자부터 허용한다.

검증 로직 수정

src/main/java/camp/woowak/lab/vendor/domain/Vendor.java

@@ -67,8 +67,9 @@ private void checkPassword(String password) throws InvalidCreationException {
 		if (password == null || password.isBlank()) {
 			throw new InvalidCreationException("Vendor password cannot be blank");
 		}
-		if (password.trim().length() > 30) {
-			throw new InvalidCreationException("Vendor password cannot be longer than 30 characters");
+		if (password.trim().length() < 8 || password.trim().length() > 30) {
+			throw new InvalidCreationException(
+				"Vendor password must be at least 8 characters and at most 30 characters");
 		}
 	}