ESlint not block Vite build when in development mode

[Tristan-WorkGH]

Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines
• [ ] ~Tests for the changes have been added (for bug fixes / features)~
• [ ] ~Docs have been added / updated (for bug fixes / features)~

Does this PR already have an issue describing the problem?

No.

What kind of change does this PR introduce?

Fix build blocked when developing with npm start command.

What is the current behavior?

When a warning is throw by ESLint (like Prettier syntax), it will block build and hot-reload.

What is the new behavior (if this is a feature change)? ESLint warnings will not be blocking in development mode only.

Does this PR introduce a breaking change or deprecate an API?

• [ ] Yes
• [x] No

If yes, please check if the following requirements are fulfilled

• [ ] ~The Breaking Change or Deprecated label has been added~
• [ ] ~The migration steps are described in the following section~

What changes might users need to make in their application due to this PR? (migration steps)

None.

Other information:

cherry pick https://github.com/gridsuite/gridstudy-app/pull/1995