test: [M3-7781 & M3-7782] - Add Cypress integration tests for Placement Group deletion flows

[jdamore-linode]

Description 📝

Adds a couple integration tests for Placement Group deletion flows:

• With Linodes attached
• Without Linodes attached

Changes 🔄

• Adds deletion tests in delete-placement-groups.spec.ts
• Fixes a mistake in PG mock utils where an empty array was being passed where an argument should've been used
• Renames mock utils file from vm-placement.ts to placement-groups.ts

How to test 🧪

We can rely on CI, or run the tests manually:

yarn && yarn build && yarn start:manager:ci, then

yarn cy:run -s "cypress/e2e/core/placementGroups/delete-placement-groups.spec.ts"

Alternatively you can use yarn cy:debug to watch the tests run.

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

[github-actions]

Coverage Report: ✅
Base Coverage: 81.82%
Current Coverage: 81.82%

[abailly-akamai]

Nice! thanks @jdamore-linode

Test looks great and is testing all the right things ✅
I'll try to get to some others this week

[dwiley-akamai]

Tests pass locally & remotely ✅
Code review ✅