Update Zig release date

[rcalixte]

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

---

Editing an existing topic or collection

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

• Content (and my changes are in index.md)

This adds precision to the release date and remove an unnecessary trailing slash.

---

This is a minor change that also attempts to kick whatever CI is needed to update this topic page.

---

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

[ahpook]

OK....