bump zig to 4301+uber1

This is a patched zig release with 13051[1]. While we are waiting for a
resolution on #13050 (which @andrewrk is working on).

[1]: https://patch-diff.githubusercontent.com/raw/ziglang/zig/pull/13051

contrib/README-patched.md

@@ -0,0 +1,33 @@
+Patched Zig release
+-------------------
+
+This file explains how this zig version was created. As of first writing,
+0.10.0-dev.4301+uber1 + https://github.com/ziglang/zig-bootstrap/pull/131
+
+Steps to re-create a patched zig:
+
+```
+$ wget https://github.com/ziglang/zig/pull/13051.patch
+$ git clone https://github.com/ziglang/zig-bootstrap; cd zig-bootstrap
+
+# if https://github.com/ziglang/zig-bootstrap/pull/131 is not merged: patch it.
+
+$ git am --directory=zig ../13051.patch
+
+$ ${EDITOR:-vi} build  # replace the hash with "+uber1" and bump the last number in ZIG_VERSION
+
+$ ./build-and-archive
+```
+
+Recent zig-bootstrap versions require cmake >= 3.19, which is available from
+ubuntu 22.04 (jammy) or debian 12 (bookworm). Otherwise CMAKE will unable to
+"Find the C compiler". A workaround:
+
+    docker run --privileged -v `pwd`:/x -w /x -ti --rm buildpack-deps:bookworm \
+        sh -c 'apt-get update && apt-get install -y cmake && exec ./build-and-archive'
+
+(`--privileged` is necessary because of devpod nuances. You can skip it if you
+don't know what is a devpod.)
+
+`build-and-archive`, this file and 13051.patch should be in the archive where
+you got your patched zig.

contrib/build-and-archive

@@ -0,0 +1,56 @@
+#!/bin/bash
+set -xeuo pipefail
+
+zig_version=$(awk -F'"' '/^ZIG_VERSION=/{print $2}' build)
+
+#./build -j$(nproc) x86_64-linux-musl baseline
+#./build -j$(nproc) x86_64-macos-none baseline
+#./build -j$(nproc) aarch64-linux-musl baseline
+#./build -j$(nproc) aarch64-macos-none apple_a14
+#./build -j$(nproc) x86_64-windows-gnu baseline
+
+rm -fr zig-linux-x86_64-${zig_version}
+rm -fr zig-macos-x86_64-${zig_version}
+rm -fr zig-linux-aarch64-${zig_version}
+rm -fr zig-macos-aarch64-${zig_version}
+rm -fr zig-windows-x86_64-${zig_version}
+
+cp -r out/zig-x86_64-linux-musl-baseline zig-linux-x86_64-${zig_version}
+cp -r out/zig-x86_64-macos-none-baseline zig-macos-x86_64-${zig_version}
+cp -r out/zig-aarch64-linux-musl-baseline zig-linux-aarch64-${zig_version}
+cp -r out/zig-aarch64-macos-none-apple_a14 zig-macos-aarch64-${zig_version}
+cp -r out/zig-x86_64-windows-gnu-baseline zig-windows-x86_64-${zig_version}
+
+for os_arch in linux-{x86_64,aarch64} macos-{x86_64,aarch64} windows-x86_64; do
+    if [[ $os_arch == windows-x86_64 ]]; then
+        zig=zig.exe
+    else
+        zig=zig
+    fi
+    mv zig-${os_arch}-${zig_version}/{bin/${zig},}
+    rmdir zig-${os_arch}-${zig_version}/bin
+
+    # copy some clarifying files for future readers
+    mkdir zig-${os_arch}-${zig_version}/patches
+    cp README-patched.md zig-${os_arch}-${zig_version}/patches/README.md
+    cp 13051.patch "$0" zig-${os_arch}-${zig_version}/patches/
+done
+
+# x86_64 should have libs in lib/, rather than in lib/zig/.
+for os in linux macos windows; do
+    mv zig-${os}-x86_64-${zig_version}/{lib,lib2}
+    mv zig-${os}-x86_64-${zig_version}/{lib2/zig,lib}
+    rmdir zig-${os}-x86_64-${zig_version}/lib2
+done
+
+tar cJf zig-linux-x86_64-${zig_version}.tar.xz zig-linux-x86_64-${zig_version}/ &
+tar cJf zig-macos-x86_64-${zig_version}.tar.xz zig-macos-x86_64-${zig_version}/ &
+tar cJf zig-linux-aarch64-${zig_version}.tar.xz zig-linux-aarch64-${zig_version}/ &
+tar cJf zig-macos-aarch64-${zig_version}.tar.xz zig-macos-aarch64-${zig_version}/ &
+
+# 7z is the quickest, so blocking on it first. Then wait for tars to complete.
+7z a zig-windows-x86_64-${zig_version}.zip zig-windows-x86_64-${zig_version}/
+wait %1 %2 %3 %4
+
+sha256sum *.tar.xz *.zip
+ls -l *.tar.xz *.zip