[native_toolchain_c] pkgs/native_toolchain_c/test/cbuilder/cbuilder_cross_android_test.dart timeout

[dcharkes]

  INFO: 2026-02-27 10:40:27.315898: Running `C:\Android\android-sdk\ndk\29.0.14206865\toolchains\llvm\prebuilt\windows-x86_64\bin\clang.exe --version`.
  TimeoutException after 0:05:00.000000: Test timed out after 5 minutes.

https://github.com/dart-lang/native/actions/runs/22482501130/job/65123913665?pr=3171

This test can time out even with 5 minutes.

We're currently running a full cross product, let's run less.