Validation for image upload disappears when fill the body input

まだ誰も着手していません。

**Describe the bug**
When creating a new blog the validators for required fields appear at the bottom of the page. They should disappear when the required fields are filled out. However, when you fill in the body input the validator for the image upload disappears.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to 'Add new blog'
2. Fill in header subheader author and body
3. Scroll down to just above the submit buttons
4. See that the validator for the image has been hidden or disappeared even though no image was uploaded

**Expected behavior**
Image validation should disappear after image was uploaded.

**Screenshots**

**Desktop (please complete the following information):**
- OS: [macOS]
- Browser [e.g. chrome,]
- Version [Version 101.0.4951.54 ]

**Additional context**
Add any other context about the problem here.
This was noticed when testing the pull request that fixed "blog not submitting when tag field empty". This was I think an issue before that bug fix tho because no code for image upload was touched from viewing the edits

「Add new blog」フォームから開始し、画像をアップロードせずにヘッダー、サブヘッダー、作成者、本文を入力して問題を再現します。フォームのバリデーションの動作を追跡し、画像がアップロードされるまで画像バリデーターが表示されたままになることを、既存の必須フィールドのバリデーションフローも含めて確認します。

索引モデルが issue の本文から書いたものです。