metropolis: replace version stamp with product info

This removes the stamped metropolis version library and the associated
stampgo infrastructure, and replaces it with the product info file.

The info is now stored in a separate file in the rootfs, instead of
embedded in the core binary. This has the benefit that the core binary
no longer needs to be relinked when stamping info changes.

The version logging in core/main, and the tconsole are updated to show
some of the additional info from the product info.

Change-Id: Ic5ed0e3598e8da71b96748e8d7abfedff41acd3f
Reviewed-on: https://review.monogon.dev/c/monogon/+/4207
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/metropolis/cli/metroctl/test/main_test.go b/metropolis/cli/metroctl/test/main_test.go
index e1ca606..b853b82 100644
--- a/metropolis/cli/metroctl/test/main_test.go
+++ b/metropolis/cli/metroctl/test/main_test.go
@@ -16,12 +16,9 @@
 
 	"github.com/bazelbuild/rules_go/go/runfiles"
 
-	mversion "source.monogon.dev/metropolis/version"
-
 	mlaunch "source.monogon.dev/metropolis/test/launch"
 	"source.monogon.dev/metropolis/test/util"
 	"source.monogon.dev/osbase/cmd"
-	"source.monogon.dev/version"
 )
 
 var (
@@ -43,6 +40,9 @@
 	}
 }
 
+// This is filled at linking time.
+var metropolisVersion string
+
 // mctlRun starts metroctl, and waits till it exits. It returns nil, if the run
 // was successful.
 func mctlRun(t *testing.T, ctx context.Context, args []string) error {
@@ -279,7 +279,7 @@
 			if want, got := "yes", ontpm; want != got {
 				return fmt.Errorf("node tpm mismatch: wanted %q, got %q", want, got)
 			}
-			if want, got := version.Semver(mversion.Version), onver; want != got {
+			if want, got := metropolisVersion, onver; want != got {
 				return fmt.Errorf("node version mismatch: wanted %q, got %q", want, got)
 			}
 			if ontimeout < 0 || ontimeout > 30 {