test: disable **again** cross-compile tests

They are very flaky now, and I can't seem to be able to put my finger
on the true cause.

.github/workflows/cross-compile.yml

@@ -26,8 +26,30 @@ jobs:
         run: just gem-cross
       - name: download pre-compiled parsers
         run: just dl-parsers linux-x64 # TODO: test on a mac?
-      - name: test cross-compiled gems
-        run: just gem-cross-test
+      # FIXME: I faced a lot of issues with gemstash while running the project
+      # with gemstash and bundler. It refuses to correctly recognize the ruby
+      # version. For instance, with ruby-version 3.3 I get this:
+      #
+      #     Because every version of ruby_tree_sitter depends on Ruby >= 3.4, < 3.5.dev
+      #       and Gemfile depends on ruby_tree_sitter = 1.11.0,
+      #       Ruby >= 3.4, < 3.5.dev is required.
+      #
+      # Yes, I am running on a ruby 3.3 and getting complaints on ruby 3.4.
+      # But even before the release of 3.4, I got:
+      #
+      #       Ruby >= 3.3, < 3.4.dev is required.
+      #
+      # So I decided to turn it off and maybe get back to it later.
+      # I looked at issues of bundler, nokogiri, gemstash, and rake-compiler-doc,
+      # and I couldn't find anyone complaining about this issue.
+      #
+      # Moreover, at one point, it started working again, and now it doesn't.
+      # So it's also very flaky.
+      #
+      # - name: test cross-compiled gems
+      #   run: just gem-cross-test
+      # - name: test cross-compiled gems
+      #   run: just gem-cross-test
       - name: package platform-agnostic gem
         run: |
           rm -rf Gemfile.lock