decap-cms-app not compatible with React 19

The build for my Gatsby app breaks when using `decap-cms-app@3.7.0` or above with React 19.

When running `npm start`, the frontend application builds fine but fails when building the CMS and the following error is displayed:

As UMD builds were removed in React 19, this errors seems to be caused by one of `decap-cms-app`'s peer dependencies needing UMD builds which were available in React 18 or below.

When installing `decap-cms-app@3.7.0` or above there are a number of npm warnings of a number of peer dependencies of `decap-cms-app` needing React 18 or below, see screenshot below:

**Expected behavior**
`decap-cms-app` should work seamlessly with React 19.

**Applicable Versions:**
- Decap CMS version: >=3.7.0
- React: 19.2.7
- Node.JS version: 24.14.1
- Gatsby: 5.14.0

Reproduce the failure with decap-cms-app 3.7.0 or above, React 19.2.7, Gatsby 5.14.0, and Node.js 24.14.1 by running npm start. Inspect the CMS build error and npm peer-dependency warnings to identify the incompatible dependency; done means the CMS builds successfully with React 19.

Written by the indexing model from the issue text.