fix: try building the npm package in CI (#2043)

Historically, the release process for the npm module has been:

- I run `codex-rs/scripts/create_github_release.sh` to kick off a
release for the native artifacts.
- I wait until it is done.
- I run `codex-cli/scripts/stage_rust_release.py` to build the npm
release locally
- I run `npm publish` from my laptop

It has been a longstanding issue to move the npm build to CI. I may
still have to do the `npm publish` manually because it requires 2fac
with `npm`, though I assume we can work that out later.

Note I asked Codex to make these updates, and while they look pretty
good to me, I'm not 100% certain, but let's just merge this and I'll
kick off another alpha build and we'll see what happens?

codex-cli/scripts/stage_rust_release.py

@@ -13,11 +13,18 @@ def main() -> int:
 
 Run this after the GitHub Release has been created and use
 `--release-version` to specify the version to release.
+
+Optionally pass `--tmp` to control the temporary staging directory that will be
+forwarded to stage_release.sh.
 """
     )
     parser.add_argument(
         "--release-version", required=True, help="Version to release, e.g., 0.3.0"
     )
+    parser.add_argument(
+        "--tmp",
+        help="Optional path to stage the npm package; forwarded to stage_release.sh",
+    )
     args = parser.parse_args()
     version = args.release_version
 
@@ -43,15 +50,17 @@ Run this after the GitHub Release has been created and use
     print(f"should `git checkout {sha}`")
 
     current_dir = Path(__file__).parent.resolve()
-    stage_release = subprocess.run(
-        [
-            current_dir / "stage_release.sh",
-            "--version",
-            version,
-            "--workflow-url",
-            workflow["url"],
-        ]
-    )
+    cmd = [
+        str(current_dir / "stage_release.sh"),
+        "--version",
+        version,
+        "--workflow-url",
+        workflow["url"],
+    ]
+    if args.tmp:
+        cmd.extend(["--tmp", args.tmp])
+
+    stage_release = subprocess.run(cmd)
     stage_release.check_returncode()
 
     return 0