✅ Tests: Update @percy/agent to fix memory leak

[Robdel12]

What is this?

Thank you @danielrozenberg for opening up this issue: percy/percy-agent#402 we recently shipped something that should fix this issue 👍

This also removes the PERCY_PROJECT env var. I'm assuming the old Puppeteer SDK needed that env var, but all new agent based SDKs don't need that env var anymore (just PERCY_TOKEN).

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here with @googlebot I signed it! and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[danielrozenberg]

Hi @Robdel12, thanks for the quick fix! We got a renovate-bot PR (#25334) to fix this, and your PR removes the PERCY_PROJECT variables (which we don't use anymore as you correctly stated) but it leaves a few more references to it (there are some places where it's percy_project, in lower-case) - do you want to push another commit to this or should I merge the other PR and remove that dangling env variable in a separate PR? :)

[Robdel12]

Ah, great point! I think merging the dependabot PR and circling back with another PR should do it 😃