relibc: start from latest upstream master (cbc14a31) + RB path deps

Upstream precedence: upstream provides eventfd, signalfd, timerfd, POSIX
stubs, cbindgen fixes, Rust 2024 edition, fenv, scheduler, and many more
that RB had previously patched. All RB patches for already-upstreamed
functionality have been dropped per the golden rule.

RB additions on top of upstream:
- Version suffix +rb0.3.1
- Path deps for redox_syscall and libredox (local fork policy)
- [patch.crates-io] for local fork resolution
- Author attribution

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "relibc"
-version = "0.2.5"
-authors = ["Jeremy Soller <jackpot51@gmail.com>"]
+version = "0.2.5+rb0.3.1"
+authors = ["Jeremy Soller <jackpot51@gmail.com>", "vasilito <adminpupkin@gmail.com>"]
 edition = "2024"
 
 [lib]
@@ -72,8 +72,8 @@ bitflags = "2"
 ioslice = { version = "0.6", default-features = false }
 plain = "0.2"
 redox-path = "0.4.0"
-redox_protocols = { package = "libredox", version = "0.1.18", default-features = false, features = ["protocol"] }
-redox_syscall = "0.9.0"
+redox_protocols = { package = "libredox", path = "../libredox", default-features = false, features = ["protocol"] }
+redox_syscall = { path = "../syscall" }
 
 [build-dependencies]
 cc = "1"
@@ -149,3 +149,5 @@ panic = "abort"
 
 [patch.crates-io]
 cc-11 = { git = "https://github.com/tea/cc-rs", branch = "riscv-abi-arch-fix", package = "cc" }
+redox_syscall = { path = "../syscall" }
+libredox = { path = "../libredox" }