[Test] Fix flaky Rage test

[PigeonBar]

Why am I making these changes?

The test could break due to the player Pokemon occasionally fainting.

What are the changes from a developer perspective?

The test now sets the player Pokemon's Defense to +6 stages to prevent it from fainting.

Screenshots/Videos

How to test the changes?

Check that the player Pokemon still survives if you override the opponents to have max IV's and a higher level.

Checklist

• I'm using beta as my base branch
• There is no overlap with another PR?
• The PR is self-contained and cannot be split into smaller PRs?
• Have I provided a clear explanation of the changes?
• Have I tested the changes manually?
• Are all unit tests still passing? (npm run test:silent

[Tempo-anon]

Thanks for helping me clean up my unit test 😭