Print OS and arch info for `--version`.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## UNRELEASED
 ### Changed
 - Properly close stream if `Ctrl+C` is pressed in interactive mode.
+- Print OS and architecture for flag `--version`.
 
 ## [v0.8.4] 2024-03-09
 ### Changed

main.go

@@ -145,6 +145,8 @@ func main() {
 	case *flagVersion:
 		// If requested, show version and quit.
 		fmt.Println("go-sendxmpp", version)
+		fmt.Println("OS:", runtime.GOOS)
+		fmt.Println("Arch:", runtime.GOARCH)
 		fmt.Println("License: BSD-2-clause")
 		os.Exit(0)
 		// Quit if Ox (OpenPGP for XMPP) is requested for unsupported operations like