v1.20251120.0

What's Changed

• adjust fetch memory usage by @mikea in https://github.com/cloudflare/workerd/pull/5550
• [nfc] Clean up string allocations by @fhanau in https://github.com/cloudflare/workerd/pull/5544
• [o11y] Make STW unused tracer warning log periodically for now by @fhanau in https://github.com/cloudflare/workerd/pull/5529
• Improve bounds check in ring buffer back() by @jasnell in https://github.com/cloudflare/workerd/pull/5556
• add nullable support to env/exports by @anonrig in https://github.com/cloudflare/workerd/pull/5545

Full Changelog: https://github.com/cloudflare/workerd/compare/v1.20251119.0...v1.20251120.0