log the fips140 mode and version

Requires go1.26 for fips140.Version()

fips140.go

@@ -0,0 +1,17 @@
+package nebula
+
+import (
+	"crypto/fips140"
+	"fmt"
+)
+
+func fips140version() string {
+	switch {
+	case fips140.Enforced():
+		return fmt.Sprintf("only,version=%s", fips140.Version())
+	case fips140.Enabled():
+		return fmt.Sprintf("on,version=%s", fips140.Version())
+	default:
+		return "off"
+	}
+}