feat(eslint-plugin-fluid): update APIs for cross 8/9 ESLint compat

[tylerbutler]

Updated the no-unchecked-record-access rule to be compatible with ESLint 9's
flat config API changes while maintaining backward compatibility with ESLint 8.

Changes:

• Updated parserServices access to use context.sourceCode.parserServices
  with fallback to context.parserServices for ESLint 8
• Created getScope helper that properly handles ESLint 9's requirement
  for node argument while supporting ESLint 8's no-argument version
• Updated all getScope() calls to pass appropriate node arguments
• Fixed getKeyValue function to use correct ESLint 9 getScope API

All tests now pass successfully.

[Copilot]

Pull Request Overview

This PR updates the eslint-plugin-fluid to maintain compatibility with both ESLint 8 and ESLint 9, addressing breaking API changes in ESLint 9's flat config system.

• Updated parser services access to use context.sourceCode.parserServices with fallback for ESLint 8
• Created helper functions for getScope() API that handles ESLint 9's requirement for node arguments
• Migrated all test files to use a unified configuration helper that supports both ESLint versions

Reviewed Changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 3 comments.

File	Description
eslintConfigHelper.js	New helper utility to create ESLint configuration compatible with both ESLint 8 and 9
no-unchecked-record-access.js	Updated parser services access and getScope() calls to support both ESLint versions
package.json	Updated dependencies and test scripts to support both ESLint 8 and 9 testing
*.test.js files	Migrated test configurations to use the new helper for cross-version compatibility

Files not reviewed (1)

• common/build/eslint-plugin-fluid/pnpm-lock.yaml: Language not supported

[tylerbutler]

@copilot Address the PR feedback.

[alexvy86]

@microsoft-github-policy-service rerun

[github-actions]

🔗 Found some broken links! 💔

Run a link check locally to find them. See
https://github.com/microsoft/FluidFramework/wiki/Checking-for-broken-links-in-the-documentation for more information.

linkcheck output

> fluid-framework-docs-site@0.0.0 ci:check-links /home/runner/work/FluidFramework/FluidFramework/docs
> start-server-and-test "npm run serve -- --no-open" 3000 check-links

1: starting server using command "npm run serve -- --no-open"
and when url "[ 'http://127.0.0.1:3000' ]" is responding with HTTP status code 200
running tests using command "npm run check-links"


> fluid-framework-docs-site@0.0.0 serve
> docusaurus serve --no-open

[SUCCESS] Serving "build" directory at: http://localhost:3000/

> fluid-framework-docs-site@0.0.0 check-links
> linkcheck http://localhost:3000 --skip-file skipped-urls.txt

 ELIFECYCLE  Command failed with exit code 1.