build with zig master also

`aarch64_32` has ceased to exist. Actually, I'm not sure it should have
been used on this switch prong anyway.

.github/workflows/ci.yaml

@@ -0,0 +1,40 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+  workflow_dispatch:
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        zig-version: ["0.13.0"]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        include:
+          - zig-version: "0.12.1"
+            os: ubuntu-latest
+          - zig-version: "master"
+            check-format: true
+            os: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Zig
+        uses: mlugg/setup-zig@v1
+        with:
+          version: ${{ matrix.zig-version }}
+
+      - if: ${{ matrix.check-format }}
+        name: Check Formatting
+        run: zig fmt --ast-check --check .
+
+      - name: Build
+        run: zig build --summary all

build.zig

@@ -319,7 +319,6 @@ pub fn build(b: *std.Build) !void {
     const conf_header = upstream.path(switch (tinfo.cpu.arch) {
         .aarch64,
         .aarch64_be,
-        .aarch64_32,
         => source_header_prefix ++ "arch/aarch64/opensslconf.h",
         .x86 => source_header_prefix ++ "arch/i386/opensslconf.h",
         .riscv64 => source_header_prefix ++ "arch/riscv64/opensslconf.h",
@@ -356,7 +355,6 @@ pub fn build(b: *std.Build) !void {
     switch (tinfo.cpu.arch) {
         .aarch64,
         .aarch64_be,
-        .aarch64_32,
         => libressl_libs.libcrypto.addIncludePath(
             upstream.path(libcrypto_src_prefix ++ "bn/arch/aarch64"),
         ),