Resolve ESLint upgrade conflicts

[pawiecz]

Client npm installation produces following deprecation warnings:

npm warn deprecated eslint@8.57.1: This version is no longer supported. Please see https://eslint.org/version-support for other options.
npm warn deprecated @humanwhocodes/config-array@0.13.0: Use @eslint/config-array instead
npm warn deprecated @humanwhocodes/object-schema@2.0.3: Use @eslint/object-schema instead

All of them are caused by keeping ESLint v8.57.1 which has reached EOL on 5.10.2024.

Attempt to upgrade to eslint@latest results in:

npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: client@1.0.0
npm error Found: eslint@10.0.0
npm error node_modules/eslint
npm error   dev eslint@"10.0.0" from the root project
npm error
npm error Could not resolve dependency:
npm error peer eslint@"^3 || ^4 || ^5 || ^6 || ^7 || ^8 || ^9.7" from eslint-plugin-react@7.37.5
npm error node_modules/eslint-plugin-react
npm error   dev eslint-plugin-react@"^7.30.1" from the root project

Although package eslint-plugin-react seems to be relatively well-maintained (with most recent release in March 2025) satisfying its requirement for ESLint ^9.7 is not a long-term solution. It would work for the next 6 months until v9 is EOL'd.