Pinned dependencies needs `rescript build -with-deps`

[jfrolich]

To build changes with pinned dependencies I need to run rescript build -with-deps. I thought that with pinned dependencies a rescript build would also build changes in the pinned dependencies (if I read the functionality correctly). That doesn't happen at the moment. If this is the correct behavior perhaps it should be documented better.

Minimally reproduced issue: https://github.com/jfrolich/rescript-reproduce-issue/tree/pinned-dependencies-issue

• run rescript build
• change something in a pinned dependency (for instance a syntax error)
• it doesn't build the changed dependency