I think there's no out-of-the-box option right now, but maybe you could use a plugin to achieve that: Eslint plugin only warn

Or set all the rules as warning instead of errors.

Following es-lint-plugin-prettier readme, edit your .eslintrc.json and put a specific rule for prettier:

"rules": {
  // maybe your other rules...

  "prettier/prettier": "warn"
}

Then, prettier rules will be issued as warnings instead of errors.

Not sure of all the side effects, but it seems to work ok for my project, where I also use @typescript-eslint/eslint-plugin, @typescript-eslint/parser, eslint-config-prettier and eslint-plugin-prettier.

If it helps, my extends config in .eslintrc.json:

"extends": [
  "eslint:recommended",
  "plugin:@typescript-eslint/eslint-recommended",
  "plugin:@typescript-eslint/recommended",
  "prettier/@typescript-eslint",
  "plugin:prettier/recommended"
],

You can create an .eslintrc file with all the rules set to "warn"

If you already have an eslintrc file you can use that, or extend from a rules file such as the one here. In this one, all the rules are set to 0 (disabled). You can modify specific ones or all of them and set them to 1 (or "warn")