Once all ESLint plugin support FlatConfig

• use eslint own types (https://eslint.org/blog/2024/09/eslint-v9.10.0-released)
• @eslint/js
• eslint-plugin-sonarjs
• @typescript-eslint/eslint-plugin
• eslint-plugin-import
• eslint-plugin-jsdoc
• eslint-plugin-perfectionist
• eslint-plugin-unicorn
• eslint-plugin-react
• eslint-plugin-lit
• ⌛️ eslint-plugin-lit-a11y
• eslint-plugin-wc
• remove as unknown as Type casts and other useless casts in configs