Update dependencies

[timea-solid]

• jest from 29.x to 30.x
• babel, husky, eslint

[Copilot]

Pull Request Overview

This PR updates multiple development dependencies to their latest versions, with a major upgrade from Jest 29.x to 30.x, and migrates ESLint configuration to the new flat config format.

• Updates Jest from version 29.x to 30.x along with related testing dependencies
• Upgrades ESLint from v8 to v9 and migrates from legacy .eslintrc to flat config format
• Updates various build tools including Babel, Husky, and lint-staged

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
package.json	Updates dependency versions and bumps package version to 2.3.0
eslint.config.mjs	Adds new ESLint flat configuration file with equivalent settings
.eslintrc	Removes legacy ESLint configuration file

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