`deno upgrade` fails in broken workspace setting in v1.45

[bartlomieju]

Version: Deno v1.45.0

$ deno upgrade
error: Could not find package.json for workspace member in 'file:///Users/ib/dev/deno_workspace_examples/buzz/'.

Reproduction: https://github.com/bartlomieju/broken_deno_upgrade_in_workspace

[dsherret]

This is essentially just https://github.com/denoland/deno/issues/20729