Fix linux build

Try to fix CI (this is what claude came up with, I have no idea why CI is
failing).

.github/actions/install/action.yml

@@ -41,6 +41,14 @@ runs:
     # Zig version used from the `minimum_zig_version` field in build.zig.zon
     - uses: mlugg/setup-zig@d1434d08867e3ee9daa34448df10607b98908d29 # v2.2.1
 
+    # Zig 0.16 writes fetched .zip archives to <global cache>/tmp but no longer
+    # creates that directory, so zip dependencies (sqlite amalgamation) fail
+    # with "failed to create temporary zip file: FileNotFound" on the fresh
+    # cache dir setup-zig points ZIG_GLOBAL_CACHE_DIR at.
+    - name: Zig 0.16 zip-fetch workaround
+      shell: bash
+      run: mkdir -p "${ZIG_GLOBAL_CACHE_DIR:-$HOME/.cache/zig}/tmp"
+
     # Rust Toolchain for html5ever
     - uses: dtolnay/rust-toolchain@2c7215f132e9ebf062739d9130488b56d53c060c # master
       with:

src/sys/net.zig

@@ -98,7 +98,7 @@ pub fn socket(domain: u32, socket_type: u32, protocol: u32) !socket_t {
     // SOCK.NONBLOCK/CLOEXEC are Zig-invented shim values); strip them and
     // apply via fcntl instead. Linux/FreeBSD accept them natively.
     const flag_bits = posix.SOCK.NONBLOCK | posix.SOCK.CLOEXEC;
-    const extra = if (comptime builtin.os.tag.isDarwin()) socket_type & flag_bits else 0;
+    const extra: u32 = if (comptime builtin.os.tag.isDarwin()) socket_type & flag_bits else 0;
     const rc = c.socket(domain, socket_type & ~extra, protocol);
     if (rc < 0) {
         return errnoError(c.errno(rc));