update to React 19.x

[foreveremain]

Czeckolada has a few deprecated npm dependencies. Would be good to fix those - ideally by upgrading to react 19.x. We could have some automated stuff for this too ?

WARN  deprecated eslint@8.57.1: This version is no longer supported. Please see https://eslint.org/version-support for other options.
 WARN  21 deprecated subdependencies found: @babel/plugin-proposal-class-properties@7.18.6, @babel/plugin-proposal-nullish-coalescing-operator@7.18.6, @babel/plugin-proposal-numeric-separator@7.18.6, @babel/plugin-proposal-optional-chaining@7.21.0, @babel/plugin-proposal-private-methods@7.18.6, @babel/plugin-proposal-private-property-in-object@7.21.11, @humanwhocodes/config-array@0.13.0, @humanwhocodes/object-schema@2.0.3, abab@2.0.6, domexception@2.0.1, glob@7.2.3, inflight@1.0.6, q@1.5.1, rimraf@3.0.2, rollup-plugin-terser@7.0.2, sourcemap-codec@1.4.8, stable@0.1.8, svgo@1.3.2, w3c-hr-time@1.0.2, workbox-cacheable-response@6.6.0, workbox-google-analytics@6.6.0
Already up to date
Progress: resolved 1301, reused 1301, downloaded 0, added 0, done
 WARN  Issues with peer dependencies found
.
└─┬ @testing-library/react 13.4.0
  └─┬ @types/react-dom 18.3.5
    └── ✕ unmet peer @types/react@^18.0.0: found 19.0.8
``

[foreveremain]

Here's a minimal patch that at least makes it possible to run Czekolada:

patch_packagejson.patch