[FSSDK-12169] package manager update

[junaed-optimizely]

This pull request updates dependencies for compatibility with newer versions of Node.js and related tooling, improves linting and code quality enforcement, and makes minor code style corrections.

• Updated package.json to require Node.js version 18 or higher and upgraded several dependencies (@types/jest, @typescript-eslint/eslint-plugin, husky, jest, lint-staged, react, etc.) to their latest major versions for improved compatibility and stability.
• Added new ESLint rules in .eslintrc.js to warn about usage of any types and unused variables, helping catch potential issues earlier in development.
• Modified the lint script in package.json to remove the --fix flag, ensuring lint errors are surfaced and not auto-fixed during CI runs.
• Updated lint-staged configuration and related scripts to use npm run instead of yarn run for consistency and compatibility with the updated environment.
• Changed the Husky pre-commit hook (.husky/pre-commit) to simplify execution by removing shell initialization, ensuring linting and tests are run before commits.
• Updated the prepare script in package.json to use the new Husky invocation method, aligning with Husky v9 requirements.

Test plan

Existing tests should pass

Issues

• FSSDK-12169

[github-actions]

Jest Coverage Report

St.❔	Category	Percentage	Covered / Total
🟢	Statements	98.95%	851/860
🟢	Branches	92.02% (+0.5% 🔼)	461/501
🟢	Functions	97.52%	157/161
🟢	Lines	99.1%	769/776

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	client.ts	99.28%	94.09% (-0.35% 🔻)	96.97%	99.5%
🟢	notifier.ts	100%	50% (-50% 🔻)	100%	100%
🟢	Experiment.tsx	96.55%	90% (-2.31% 🔻)	100%	96.15%

Test suite run success

266 tests passing in 10 suites.

Report generated by 🧪jest coverage report action from dd4415a