Separate docs build and deploy into separate workflows

This should remove the annoying "@asmeurer deployed to docs-build-and-deploy
10 minutes ago — with GitHub Actions" after every single commit in the pull
request timeline.

Author: asmeurer

.github/workflows/build-docs.yml

@@ -0,0 +1,22 @@
+name: Docs Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+      - name: Install Dependencies
+        run: |
+          python -m pip install -r docs/requirements.txt
+      - name: Build Docs
+        run: |
+          cd docs
+          make html
+      - name: Upload Artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: docs-build
+          path: docs/_build/html

.github/workflows/deploy-docs.yml

@@ -0,0 +1,27 @@
+name: Docs Deploy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    environment:
+      name: docs-deploy
+    steps:
+      - name: Download Artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: docs-build
+
+      # Note, the gh-pages deployment requires setting up a SSH deploy key.
+      # See
+      # https://github.com/JamesIves/github-pages-deploy-action/tree/dev#using-an-ssh-deploy-key-
+      - name: Deploy
+        uses: JamesIves/github-pages-deploy-action@v4
+        with:
+          folder: .
+          ssh-key: ${{ secrets.DEPLOY_KEY }}
+          force: no