[js] Upgrade ESLint from v8 to v9 for subfolder /js/

[fs-eire]

Description

[js] Upgrade ESLint from v8 to v9 for subfolder /js/

Motivation and Context

[Copilot]

Pull Request Overview

This PR upgrades ESLint from version 8 to version 9 for the /js/ folder, migrating from the legacy .eslintrc.js configuration format to the new flat config format (eslint.config.mjs). The upgrade also includes updates to related ESLint plugins and adapts the codebase to comply with new linting rules.

• Migrated ESLint configuration from .eslintrc.js to flat config format eslint.config.mjs
• Upgraded ESLint and related plugins to their latest versions
• Replaced deprecated expect().to.be.true/false assertions with explicit error throwing
• Removed unnecessary ESLint disable comments that are no longer needed

Reviewed Changes

Copilot reviewed 28 out of 30 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
js/package.json	Updated ESLint and plugin dependencies to v9-compatible versions
js/eslint.config.mjs	New flat config format with equivalent rule configuration
js/.eslintrc.js	Removed legacy configuration file
js/web/test/unittests/opset.ts	Replaced expect assertion with explicit error throw
js/web/test/test-runner.ts	Replaced expect assertion with explicit error throw
js/web/test/test-types.ts	Removed no-namespace disable comment
js/node/test/unittests/lib/tensor.ts	Refactored ternary expressions to if/else blocks
js/react_native/e2e/src/App.tsx	Updated deprecated ban-types to no-empty-object-type
Multiple files	Removed unnecessary eslint-disable comments and unused catch variables

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