Update sphinx-docs workflow

Author: aurebidart

.github/workflows/sphinx-docs.yml

@@ -27,16 +27,19 @@ jobs:
 
       - name: Install dependencies for Python client docs
         working-directory: ./client/python/projectairsim/docs
-        run: |
-          pip install -r requirements.txt
+        run: pip install -r requirements.txt
 
       - name: Build Python client docs
         working-directory: ./client/python/projectairsim/docs
-        run: make html
+        run: |
+          rm -rf build
+          make html
 
       - name: Build main docs
         working-directory: ./docs
-        run: make html
+        run: |
+          rm -rf build
+          make html
 
       - name: Copy Python client docs into main docs
         run: |