Guardian Apply job fails when the message body is too long

### TL;DR

`Apply Terraform` succeeded, but then it showed a failure due to the message being too long, causing the GH action step to be marked as failed, and skipping the next steps (Post Mint Token, and anything after).

```
Run guardian apply \
Starting Guardian apply
Downloading Guardian plan file
Writing plan file to disk
Creating start comment
Running Terraform commands
Initializing Terraform
Validating Terraform
Applying Terraform
Formatting output
Updating result comment
Deleting Guardian plan file
failed to write result comment: failed to create apply comment: failed to update pull request comment: failed to execute retriable function: failed to update pull request comment: PATCH https://api.github.com/repos/taara-co/gcp-org/issues/comments/2814581792: 422 Validation Failed [{Resource:IssueComment Field:body Code:custom Message:body is too long (maximum is 655[36](https://github.com/taara-co/gcp-org/actions/runs/14530265125/job/40768754066#step:9:37) characters)}]
```

### Expected behavior

_No response_

### Observed behavior

_No response_

### Environment Details

```markdown
Current runner version: '2.323.0'
Operating System
Ubuntu
24.04.2
LTS
Runner Image
Image: ubuntu-24.04
Version: 20250413.1.0
Included Software: https://github.com/actions/runner-images/blob/ubuntu24/20250413.1/images/ubuntu/Ubuntu2404-Readme.md
Image Release: https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20250413.1
Runner Image Provisioner
2.0.422.1
GITHUB_TOKEN Permissions
Contents: read
Metadata: read
PullRequests: write
Secret source: Actions
Prepare workflow directory
Prepare all required actions
Getting action download info
Download action repository 'actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683' (SHA:11bd71901bbe5b1630ceea73d27597364c9af683)
Download action repository 'google-github-actions/auth@6fc4af4b145ae7821d527454aa9bd537d1f2dc5f' (SHA:6fc4af4b145ae7821d527454aa9bd537d1f2dc5f)
Download action repository 'abcxyz/github-token-minter@3d06f6c61a3a3b28fc241a5105ee484c3c529f5f' (SHA:3d06f6c61a3a3b28fc241a5105ee484c3c529f5f)
Download action repository 'abcxyz/secure-setup-terraform@7f93ab7480b59d0b9c03d7128402eb7e19148b4d' (SHA:7f93ab7480b59d0b9c03d7128402eb7e19148b4d)
Download action repository 'abcxyz/pkg@3fe0963bdeae890e770c33f2bb30cfcfb5229b41' (SHA:3fe0963bdeae890e770c33f2bb30cfcfb5229b41)
Getting action download info
Download action repository 'hashicorp/setup-terraform@651471c36a6092792c552e8b1bef71e592b462d8' (SHA:651471c36a6092792c552e8b1bef71e592b462d8)
Getting action download info
Download action repository 'actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57' (SHA:1bd1e32a3bdc45362d1e726936510720a7c30a57)
```

### Additional information

_No response_

Guardian が 65536 文字を超える本文で GitHub コメントを更新しようとすると、エラーが発生します。apply の出力をフォーマットし、pull request のコメントを作成／更新するコードを探してください。これを処理しているファイルは Guardian リポジトリ内、おそらくコメント作成ロジックの周辺にあります。メッセージがどこで組み立てられ、切り詰められているかを確認してください。コメント更新に関連する既存のテストを実行すると、修正を検証できます。

索引モデルが issue の本文から書いたものです。