Removed Pyxel game engine

[AdamHarte]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• I am not the sole author or employee of a company who created either the topic I am modifying/adding or the collection entry I am modifying/adding.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

---

Editing an existing topic or collection

I'm suggesting these edits to an existing topic or collection:

• Image (and my file is *.png, square, dimensions 288x288, size <= 75 kB)
• Content (and my changes are in index.md)

Looks like the Pyxel game engine was mistaken for the PyxelEdit pixel art software, which is not opensource. So I removed it, as the game engine is not a "Pixel Art Tool".

---

Please note: we will close your PR without comment if you do not check the boxes above and provide ALL requested information.

[AdamHarte]

Failing tests because:

Error: expected collection changes to have been appended to the existing item list

Seems like a bad test, because not all changes are additions. Does this mean that nobody can ever remove items?

[jmeridth]

Failing tests because:

Error: expected collection changes to have been appended to the existing item list

Seems like a bad test, because not all changes are additions. Does this mean that nobody can ever remove items?

@AdamHarte That's a fair statement. I'm good to merge this and then let the collection action generate the PR that will make this happy. Chicken/egg. I will take a look at it soon to hopefully allow just deletions with no issues.

[jmeridth]

@AdamHarte thank you for helping us keep these collections clean. 🙇

[AdamHarte]

@jmeridth No worries at all. Thank you for sorting this out. I was starting to get worried I was not going to be able to get this change through. :)