Alexis Cote

`join` command regression: decorators/preprocessor are always executed

1

**Describe the bug** Before [this commit](https://github.com/Redocly/openapi-cli/commit/b53e9e4acbd694ac4b0aa4c8f09fc4c5b6f95901), the join command wasn't bundling documents. By changing this behaviour, running a join now always execute the decorators/preprocessor. For us, it's a regression because...