chore: migrate to ESLint extends config structure

[MikeMcC399]

Supersedes related Renovate PRs:

• chore(deps): update dependency eslint-plugin-cypress to v5.2.0 #1525
• chore(deps): update dependency @stylistic/eslint-plugin to v5.5.0 #1542

Situation

The ESLint 9.22.0 release provided a new config feature described in the blog article Evolving flat config with extends and which is now the documented way to construct ESLint Configuration Files.

The ESLint configuration eslint.config.mjs does not yet use this feature. The new functionality would allow constructing this ESLint config in a simpler and more maintainable way.

Change

The ESLint configuration is simplified and updated, in detail as follows. Minor example source code linting fixes are carried out.

• Update the ESLint configuration eslint.config.mjs to use the defineConfig() function, imported from the eslint/config entrypoint according to the Configuration Files documentation.

• Align import naming for best agreement with ESLint and eslint-plugin-cypress documentation

• Update to latest ESLint components

• Fix recommended rule violations

  • @stylistic/eol-last
  • @stylistic/key-spacing

• Add rules and fix violations:

  • @stylistic/arrow-parens using ['error', 'always']
  • @stylistic/space-before-function-paren using ['error', 'always']

Note that only example sources are changed, so this PR does not cause any version update to the action itself.

Verification

git clean -xfd
npm ci
npm run lint

Confirm no errors reported and no changes suggested.

[cypress-app-bot]

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