chore(ESLint): update ESLint dependency to v9.x and move to flat config

[dgonzalezr]

Description

This PR updates ESLint to the last major version, v9.x, and all its related dependencies. It also moves from .json configuration to flat config in all packages/*, now the default with the latest ESLint.

Related Issue

N/A

Documentation

Screenshots (if applicable)

Checklist

• I have read the CONTRIBUTING document.
• I have read the CODE OF CONDUCT document.
• I have reviewed my code.
• I have tested the changes locally.
• I have updated the documentation (if applicable).
• I have added unit tests and e2e tests (if applicable).
• I have requested reviews from relevant team members.

Additional Notes

[nx-cloud]

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✅ Successfully ran 5 targets

• nx run beeq:storybook-build --output-style=stream-without-prefixes
• nx affected -t e2e --exclude=*,!tag:core --parallel=3 --base=5056a45375f29085d1879a190d3d49caf3abaf22 --head=7a3590b19cacb39442ffd6c7300541a582486692 --ci --code-coverage --runInBand
• nx affected -t build --exclude=*,!tag:publishable --parallel=3 --base=5056a45375f29085d1879a190d3d49caf3abaf22 --head=7a3590b19cacb39442ffd6c7300541a582486692
• nx affected -t test --exclude=*,!tag:core --parallel=3 --base=5056a45375f29085d1879a190d3d49caf3abaf22 --head=7a3590b19cacb39442ffd6c7300541a582486692 --ci --runInBand
• nx affected -t lint --exclude=*,!tag:publishable --parallel=3 --base=5056a45375f29085d1879a190d3d49caf3abaf22 --head=7a3590b19cacb39442ffd6c7300541a582486692

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud