build: use Zig via ziglang PyPI package

This avoids cluttering workdir with unpacked tarball
and will work automatically once PEP-723 is implemented.

scripts/zig-cc

@@ -1,7 +1,13 @@
 #!/usr/bin/env python
+# /// pyproject
+# [run]
+# dependencies = [
+#   "ziglang==0.11.0"
+# ]
+# ///
+import os
 import subprocess
 import sys
-import os
 
 
 def flag_filter(flag: str) -> bool:
@@ -34,7 +40,17 @@ def main():
     args += ["-DBROKEN_CLANG_ATOMICS"]
 
     subprocess.run(
-        ["zig", "cc", "-target", zig_target, *zig_cpu_args, *args], check=True
+        [
+            sys.executable,
+            "-m",
+            "ziglang",
+            "cc",
+            "-target",
+            zig_target,
+            *zig_cpu_args,
+            *args,
+        ],
+        check=True,
     )
 
 

scripts/zig-rpc-server.sh

@@ -10,14 +10,6 @@ unset RUSTFLAGS
 # Pin Rust version to avoid uncontrolled changes in the compiler and linker flags.
 export RUSTUP_TOOLCHAIN=1.72.0
 
-ZIG_VERSION=0.11.0
-
-# Download Zig
-rm -fr "$ZIG_VERSION" "zig-linux-x86_64-$ZIG_VERSION.tar.xz"
-wget "https://ziglang.org/builds/zig-linux-x86_64-$ZIG_VERSION.tar.xz"
-tar xf "zig-linux-x86_64-$ZIG_VERSION.tar.xz"
-export PATH="$PWD/zig-linux-x86_64-$ZIG_VERSION:$PATH"
-
 rustup target add i686-unknown-linux-musl
 CC="$PWD/scripts/zig-cc" \
 TARGET_CC="$PWD/scripts/zig-cc" \