ci: upload nightly wheels to Anaconda (#1081)

See
scientific-python/upload-nightly-action#124.

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

.github/workflows/nightlies.yml

@@ -0,0 +1,45 @@
+name: Anaconda Cloud nightly wheels
+
+on:
+  # Run daily at 1:23 UTC
+  schedule:
+    - cron: 23 1 * * *
+  # Run on demand with workflow dispatch
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build_wheel:
+    name: Build and upload wheel
+    if: github.repository_owner == 'scikit-build'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: hynek/build-and-inspect-python-package@v2
+
+  upload_nightly_wheels:
+    name: Upload nightly wheels to Anaconda Cloud
+    if: github.repository_owner == 'scikit-build'
+    needs: [build_wheel]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: Packages
+          path: dist
+
+      - name: List wheel to be deployed
+        run: ls -lha dist/*.whl
+
+      - name: Upload wheel to Anaconda Cloud as nightly
+        uses: scientific-python/upload-nightly-action@b36e8c0c10dbcfd2e05bf95f17ef8c14fd708dbf # 0.6.2
+        with:
+          artifacts_path: dist
+          anaconda_nightly_upload_token:
+            ${{ secrets.ANACONDA_ORG_UPLOAD_TOKEN }}