feat: add error message when toCommit does not exist

[weyert]

Adds an error message when the toCommit for the --filter=[from...to] filter is invalid

[vercel[bot]]

@weyert is attempting to deploy a commit to the Vercel Team on Vercel.

A member of the Team first needs to authorize it.

[tknickman]

@weyert apologies for letting this stagnate! We're moving this portion over to rust now (new version is here! https://github.com/vercel/turbo/blob/main/crates/turborepo-scm/src/git.rs#L22) so I'm going to close this one out and we'll re-implement.

Thanks!