fix(core): make Unix pipe fd ownership explicit

[nathanwhit]

Summary

• keep raw Unix pipe descriptors owned by the pipe handle until ownership is transferred
• make Tokio streams and listeners the sole closer after connect, accept, or listen
• retain explicit cleanup for descriptor-only pipes and non-owning AsyncFd registrations
• cover raw, listener, accepted-stream, and bound-connect ownership transitions

Tests

• ./tools/format.js
• cargo test -p deno_core 'uv_compat::tests' --lib
• cargo clippy -p deno_core --lib --no-deps -- -D warnings
• cargo build -p deno --bin deno