Outdated deps warning can be misleading when run from workspace directory

[johanbrandhorst]

Steps to reproduce:

1. Create a new workspace:

   version: v1
   directories:
     - proto
   

2. Create a new module with at least one dependency in the proto directory:

   version: v1
   name: buf.build/whatever/whatever
   deps:
     - buf.build/googleapis/googleapis
   lint:
     use:
       - DEFAULT
   breaking:
     use:
       - FILE
   

3. Run buf lint from the workspace directory:

   $ buf lint
   WARN    Specified deps are not covered in your buf.lock, run "buf mod update":
           - buf.build/googleapis/googleapis
   Failure: no .proto target files found # ignore this part
   

The misleading instructions here being that the user should run buf mod update inside the workspace directory, when it's really needed inside the proto directory.

[DennisPing]

As a student, I found this ticket especially important. Some tutorials/guides (written in 2021-2022) contain this exact typo and it is a blocker. Without finding this ticket, I could not have proceeded with learning buf & grpc-gateway.

[bufdev]

This is going to change imminently, we're redoing workspaces in a v2 of the config files.