chore: pin fflate@0.8.2

[fasttime]

Prerequisites checklist

• I have read the contributing guidelines.

AI acknowledgment

• I did not use AI to generate this PR.
• (If the above is not checked) I have reviewed the AI-generated content before submitting.

What is the purpose of this pull request?

Similar to eslint/eslint#20877 and eslint/rewrite#458.

This PR fixes a failure when running lint:types scripts. An example in CI:

https://github.com/eslint/js/actions/runs/25960118925/job/76343013673

Run npm run lint:types

> lint:types
> npm run lint:types --workspaces --if-present


> eslint-scope@9.1.2 lint:types
> attw --pack

error while checking file:
Cannot read properties of undefined (reading 'filename')
npm error Lifecycle script `lint:types` failed with error:
npm error code 3
npm error path /home/runner/work/js/js/packages/eslint-scope
npm error workspace eslint-scope@9.1.2
npm error location /home/runner/work/js/js/packages/eslint-scope
npm error command failed
npm error command sh -c attw --pack

...

What changes did you make? (Give an overview)

As explained in arethetypeswrong/arethetypeswrong.github.io#258, the problem is caused by @arethetypeswrong/core relying on an internal behavior of fflate, which has changed in recently released v0.8.3.

This PR adds an overrides to package.json to pin fflate to v0.8.2 for @arethetypeswrong/core.

Related Issues

refs eslint/eslint#20877
refs eslint/rewrite#458

Is there anything you'd like reviewers to focus on?

[Pixel998]

LGTM, thanks!