This permits other programs (in other repos) to conditionally
import ipn/store/awsstore and/or ipn/store/kubestore and have them
register themselves, rather than feature/condregister doing it.
Updates tailscale/corp#32922
Change-Id: I2936229ce37fd2acf9be5bf5254d4a262d090ec1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Otherwise they're uselessly imported by tsnet applications, even
though they do nothing. tsnet applications wanting to use these
already had to explicitly import them and use kubestore.New or
awsstore.New and assign those to their tsnet.Server.Store fields.
Updates #12614
Change-Id: I358e3923686ddf43a85e6923c3828ba2198991d4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>