perf: launch background tasks immediately

[CPunisher]

Summary

Currently the main tasks run in the scheduler thread. If there's a time consuming main task, the scheduler thread will get stuck and doesn't have time to launch the background tasks.

This pr prevents the background tasks from being put into the task queue. Instead, the scheduler launches them as soon as they are returned.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

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[github-actions]

📝 Benchmark detail: Open

Name	Base (2025-05-27 890ae6d)	Current	Change
10000_big_production-mode_disable-minimize + exec	35.3 s ± 228 ms	36.5 s ± 439 ms	+3.25 %
10000_development-mode + exec	1.88 s ± 44 ms	1.81 s ± 14 ms	-3.96 %
10000_development-mode_hmr + exec	772 ms ± 10 ms	750 ms ± 27 ms	-2.80 %
10000_production-mode + exec	2.33 s ± 38 ms	2.31 s ± 85 ms	-0.59 %
10000_production-mode_persistent-cold + exec	2.48 s ± 17 ms	2.45 s ± 50 ms	-1.28 %
10000_production-mode_persistent-hot + exec	1.77 s ± 14 ms	1.73 s ± 13 ms	-2.48 %
arco-pro_development-mode + exec	1.81 s ± 120 ms	1.81 s ± 53 ms	+0.01 %
arco-pro_development-mode_hmr + exec	383 ms ± 3 ms	384 ms ± 4.7 ms	+0.06 %
arco-pro_production-mode + exec	3.42 s ± 64 ms	3.47 s ± 79 ms	+1.50 %
arco-pro_production-mode_generate-package-json-webpack-plugin + exec	3.56 s ± 195 ms	3.62 s ± 60 ms	+1.62 %
arco-pro_production-mode_persistent-cold + exec	3.54 s ± 164 ms	3.61 s ± 260 ms	+1.95 %
arco-pro_production-mode_persistent-hot + exec	2.13 s ± 31 ms	2.19 s ± 216 ms	+2.88 %
arco-pro_production-mode_traverse-chunk-modules + exec	3.46 s ± 87 ms	3.52 s ± 60 ms	+1.78 %
large-dyn-imports_development-mode + exec	2.1 s ± 29 ms	2.04 s ± 25 ms	-3.26 %
large-dyn-imports_production-mode + exec	2.1 s ± 21 ms	2.12 s ± 101 ms	+1.06 %
threejs_development-mode_10x + exec	1.69 s ± 88 ms	1.65 s ± 27 ms	-2.71 %
threejs_development-mode_10x_hmr + exec	871 ms ± 15 ms	851 ms ± 11 ms	-2.38 %
threejs_production-mode_10x + exec	5.25 s ± 181 ms	5.22 s ± 316 ms	-0.55 %
threejs_production-mode_10x_persistent-cold + exec	5.31 s ± 294 ms	5.3 s ± 379 ms	-0.27 %
threejs_production-mode_10x_persistent-hot + exec	4.43 s ± 87 ms	4.43 s ± 189 ms	-0.00 %
10000_big_production-mode_disable-minimize + rss memory	9266 MiB ± 98.9 MiB	9141 MiB ± 136 MiB	-1.34 %
10000_development-mode + rss memory	651 MiB ± 15.8 MiB	657 MiB ± 32.1 MiB	+0.87 %
10000_development-mode_hmr + rss memory	786 MiB ± 14.7 MiB	786 MiB ± 17 MiB	-0.04 %
10000_production-mode + rss memory	644 MiB ± 1.84 MiB	666 MiB ± 32.6 MiB	+3.50 %
10000_production-mode_persistent-cold + rss memory	768 MiB ± 44.4 MiB	771 MiB ± 51.8 MiB	+0.42 %
10000_production-mode_persistent-hot + rss memory	762 MiB ± 44.3 MiB	738 MiB ± 13.8 MiB	-3.15 %
arco-pro_development-mode + rss memory	593 MiB ± 32.5 MiB	591 MiB ± 60.7 MiB	-0.26 %
arco-pro_development-mode_hmr + rss memory	501 MiB ± 44.7 MiB	509 MiB ± 42.1 MiB	+1.56 %
arco-pro_production-mode + rss memory	686 MiB ± 65.2 MiB	721 MiB ± 65.5 MiB	+5.04 %
arco-pro_production-mode_generate-package-json-webpack-plugin + rss memory	688 MiB ± 29.7 MiB	713 MiB ± 47.4 MiB	+3.67 %
arco-pro_production-mode_persistent-cold + rss memory	780 MiB ± 90.9 MiB	773 MiB ± 36.6 MiB	-0.81 %
arco-pro_production-mode_persistent-hot + rss memory	638 MiB ± 63.1 MiB	649 MiB ± 82.4 MiB	+1.74 %
arco-pro_production-mode_traverse-chunk-modules + rss memory	697 MiB ± 52.6 MiB	736 MiB ± 64.4 MiB	+5.58 %
large-dyn-imports_development-mode + rss memory	661 MiB ± 5.06 MiB	680 MiB ± 7.49 MiB	+2.80 %
large-dyn-imports_production-mode + rss memory	544 MiB ± 6.26 MiB	564 MiB ± 11.3 MiB	+3.67 %
threejs_development-mode_10x + rss memory	604 MiB ± 20.7 MiB	622 MiB ± 24.3 MiB	+2.91 %
threejs_development-mode_10x_hmr + rss memory	739 MiB ± 20 MiB	734 MiB ± 28.9 MiB	-0.59 %
threejs_production-mode_10x + rss memory	882 MiB ± 18.1 MiB	902 MiB ± 20.2 MiB	+2.18 %
threejs_production-mode_10x_persistent-cold + rss memory	952 MiB ± 37.5 MiB	966 MiB ± 30.1 MiB	+1.56 %
threejs_production-mode_10x_persistent-hot + rss memory	847 MiB ± 18 MiB	842 MiB ± 18.5 MiB	-0.59 %

[codspeed-hq]

CodSpeed Performance Report

Merging #10484 will not alter performance

_{Comparing CPunisher:05-27-perf/sync-task (649da70) with main (60e8b26)}

🎉 Hooray! codspeed-node just leveled up to 4.0.1!

A heads-up, this is a breaking change and it might affect your current performance baseline a bit. But here's the exciting part - it's packed with new, cool features and promises improved result stability 🥳!
Curious about what's new? Visit our releases page to delve into all the awesome details about this new version.

Summary

✅ 11 untouched benchmarks