Skip test-all for annocheck

It started to fail since totally unrelated changes. It suddenly gets
killed by SIGTERM only on this environment:
https://github.com/ruby/ruby/actions/runs/4340112185/jobs/7578344307

For now, we have no idea how to fix this, so let me skip this until we
figure it out.

.github/workflows/annocheck.yml

@@ -124,8 +124,8 @@ jobs:
         if: ${{ matrix.entry.check }}
       - run: make test-tool
         if: ${{ matrix.entry.check }}
-      - run: make test-all TESTS='-- ruby -ext-'
-        if: ${{ matrix.entry.check }}
+      # - run: make test-all TESTS='-- ruby -ext-'
+      #   if: ${{ matrix.entry.check }}
       - run: make test-spec
         env:
           CHECK_LEAKS: true