fix: ensure we bind oohelperd with the repo's version number (#558)

Work related to https://github.com/ooni/probe/issues/1506#issuecomment-949715707.

This diff cherry-picks from the release/3.11 branch.

internal/cmd/printversion/main.go

@@ -0,0 +1,12 @@
+// Command printversion prints the current version of this repository.
+package main
+
+import (
+	"fmt"
+
+	"github.com/ooni/probe-cli/v3/internal/version"
+)
+
+func main() {
+	fmt.Println(version.Version)
+}