refactor(dev-infra): do not print git commands in silent mode (#38656)
refactor(dev-infra): do not print git commands in silent mode (#38656)

The git client respects the `SpawnSyncOptions` when a command
is executed. Currently it does not hide the command info
messages when commands are run in silent mode.

We fix this as part of this commit, so that the command info
is only printed to `debug` if `stdio` is set to `ignore`.

Additonally, the github token is made public so that it can be
used by commands if other repositories like forks are targeted.

PR Close #38656

angular/dev-infra,angular/dev-infra,angular/dev-infra,angular/dev-infra