bindings.ruby : fix git ls-files to include submodules

This commit updates the `git ls-files` command in the Ruby bindings
to include submodules.

The motivation for this change is that without it the rake command will
fail as all needed file will not be copied.

Author: danbev

bindings/ruby/extsources.rb

@@ -1,6 +1,6 @@
 require "yaml"
 
-sources = `git ls-files -z ../..`.split("\x0")
+sources = `git ls-files -z ../.. --recurse-submodules`.split("\x0")
 paths = YAML.load_file("../../.github/workflows/bindings-ruby.yml")[true]["push"]["paths"]
 paths.delete "bindings/ruby/**"
 EXTSOURCES = (Dir.glob(paths, base: "../..").collect {|path| "../../#{path}"} << "../../LICENSE") & sources