YJIT: CI: Extend SYNTAX_SUGGEST_TIMEOUT for macOS

To make it the same as the Ubuntu job. To avoid timeout failures due to
added compilation time in call-threshold=1 runs.

See: https://github.com/ruby/ruby/actions/runs/9317760443/job/25648721990

.github/workflows/yjit-macos.yml

@@ -135,6 +135,7 @@ jobs:
         env:
           RUBY_TESTOPTS: '-q --tty=no'
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          SYNTAX_SUGGEST_TIMEOUT: '5'
           PRECHECK_BUNDLED_GEMS: 'no'
         continue-on-error: ${{ matrix.continue-on-test_task || false }}