How to disable Prettier as a secondary formatter when the main formatter ignores a file?

[PaulRBerg]

I have a repo in which I am using both Biome and Prettier for formatting my files. Biome is for JS/TS and Prettier is for MD/YML.

I have the following paths in my .prettierignore:

**/generated
**/_generated

And the following VSCode settings:

  "biome.enabled": true,
  "editor.codeActionsOnSave": {
    "quickfix.biome": "always",
    "source.organizeImports.biome": "always"
  },
  "[javascript][json][jsonc][typescript]": {
    "editor.defaultFormatter": "biomejs.biome"
  },
  "[md][yaml]": {
    "editor.defaultFormatter": "esbenp.prettier-vscode"
  },

When I open a JS file located under a _generated directory, I see in the VSCode logs that Biome is correctly ignoring the file, but Prettier 'takes over' and formats the file upon saving it (CMD+S).

Why doesn't this work? Is it a bug in Prettier? It looks like my the paths in my .prettierignore file are not respected.