ci(docs): add sphinx dependencies to workflow

Add necessary Sphinx dependencies to the GitHub Actions
workflow to ensure documentation can be built successfully.

Author: yiwenlu66

.github/workflows/build.yml

@@ -20,6 +20,13 @@ jobs:
       with:
         python-version: 3.12
 
+    - name: Install dependencies
+      run: |
+        pip install sphinx
+        pip install sphinx-rtd-theme
+        pip install sphinx-autodoc-typehints
+        pip install myst-parser
+
     - name: Build Sphinx documentation
       run: |
         sphinx-build -b html docs build