`Assessment`: Note input visible when no more submissions are assessable

[Strohgelaender]

Describe the bug

After all available submissions are assessed manually, an small information is shown. This includes the input for internal assessment notes, but for no submissions, it should also not be possible to input any notes.

To Reproduce

1. As a Tutor, assess all available submissions for an exercise (with manual assessment enabled)
2. Press on next submission after completing the last one.
3. See the assessment note input at the bottom.

Expected behavior

The input should be hidden and only shown while assessing a specific submission.

Screenshots

Which version of Artemis are you seeing the problem on?

7.4.6 (develop)

What browsers are you seeing the problem on?

Firefox

Additional context

The screenshot above is for programming exercises, I did not test if that is the case for other exercise types as well.

Relevant log output

No response