Turbopack: perf: Fix unused argument filtering optimization in turbo-tasks for `self` arguments (#86231)
Should fix https://github.com/vercel/next.js/pull/86203
## Validation
I ran:
```
rm -rf .next && NEXT_TURBOPACK_TASK_STATISTICS=~/stats-with-fix.json pnpm next build --turbopack --experimental-build-mode=compile
```
over vercel-site and used `jq '[.[].cache_miss]|add'
~/stats-with-fix.json` and `jq '[.[].cache_hit]|add'
~/stats-with-fix.json` to measure the total cache hits/misses. These
numbers are pretty stable from run-to-run (`cache_miss` shows zero
variance, `cache_hit` shows a minor variance) because Turbopack is
(mostly) deterministic.
**Canary:**
```
cache_miss: 8603613
cache_hit: 34824116
```
**With This Fix:**
```
cache_miss: 8602660
cache_hit: 34825148
```
The difference is surprisingly small (much less than 1%), but it's still
an improvement.