feature(ci): updload nightly wheel to scientific python anaconda repo

.github/workflows/nightly_wheels.yml

@@ -0,0 +1,37 @@
+name: Nightly Wheels
+
+on:
+  schedule:
+    # Run nightly at 2 AM UTC
+    - cron: '0 2 * * *'
+  workflow_dispatch:
+
+jobs:
+  build_and_upload_nightly:
+    name: Build and upload nightly wheels
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          submodules: true
+          fetch-depth: 0
+
+      - uses: actions/setup-python@v6
+        name: Install Python
+        with:
+          python-version: '3.13'
+
+      - name: Install build dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install hatch
+
+      - name: Build wheel and sdist
+        run: hatch build
+
+      - name: Upload nightly wheels
+        uses: scientific-python/upload-nightly-action@82396a2ed4269ba06c6b2988bb4fd7672769da06
+        with:
+          artifacts_path: dist
+          anaconda_nightly_upload_token: ${{ secrets.ANACONDA_ORG_UPLOAD_TOKEN }}

changes/3449.misc.rst

@@ -0,0 +1 @@
+Publish nightly wheels to https://anaconda.org/scientific-python-nightly-wheels/.

docs/user-guide/installation.rst

@@ -42,6 +42,19 @@ Zarr is also published to `conda-forge <https://conda-forge.org>`_. Install it u
 Conda does not support optional dependencies, so you will have to manually install any packages
 needed to enable extra functionality.
 
+Nightly wheels
+--------------
+
+Development wheels are built nightly and published to the `scientific-python-nightly-wheels <https://anaconda.org/scientific-python-nightly-wheels>`_ index. To install the latest nightly build:
+
+.. code-block:: console
+
+    $ pip install --pre \
+        --extra-index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple \
+        zarr
+
+Note that nightly wheels may be unstable and are intended for testing purposes.
+
 Dependency support
 ------------------
 Zarr has endorsed `Scientific-Python SPEC 0 <https://scientific-python.org/specs/spec-0000/>`_ and now follows the version support window as outlined below: