test: Remove committed Cypress screenshots, simplify .gitignore rules

Description 📝

This is a super tiny PR that deletes the screenshots saved in cypress/screenshots and simplifies the .gitignore rule around that.

These files are super old remnants of (I think?) a visual regression testing implementation we used to have, but soon we'll be uploading test failure screenshots as artifacts in CI, and these files being here makes that difficult (since they'll show up in the artifacts, too).

(We still have plans to implement visual regression testing, and getting rid of these snapshots won't get in the way of that at all)

Changes 🔄

Deleted files in cypress/screenshots directory
Removed existing .gitignore rules for screenshots dir and add a new rule that's consistent with other Cypress output (recordings, results)

Target release date 🗓️

N/A

How to test 🧪

No testing needed since nothing depends on these files existing.

As an Author I have considered 🤔

Check all that apply

[ ] 👀 Doing a self review
[ ] ❔ Our contribution guidelines
[ ] 🤏 Splitting feature into small PRs
[ ] ➕ Adding a changeset
[ ] 🧪 Providing/Improving test coverage
[ ] 🔐 Removing all sensitive information from the code and PR description
[ ] 🚩 Using a feature flag to protect the release
[ ] 👣 Providing comprehensive reproduction steps
[ ] 📑 Providing or updating our documentation
[ ] 🕛 Scheduling a pair reviewing session
[ ] 📱 Providing mobile support
[ ] ♿ Providing accessibility support

linode / manager