update sdk-go along with pomerium core (#1427)

We currently have two copies of the core config protos in the dependency
tree: one from pomerium/pomerium, and one from pomerium/sdk-go (for the
unified API / connect-rpc support). If these two get out of sync,
settings may not serialize correctly. For now, let's mitigate this issue
by syncing both of these modules in the update-dependencies script.

Author: kenjenkins

scripts/update-dependencies

@@ -18,6 +18,7 @@ update-pomerium() {
 	require-command go
 
 	go get -u github.com/pomerium/pomerium@main
+	go get -u github.com/pomerium/sdk-go@main
 	go mod tidy
 
 	popd