Remove pip install steps in workflows (now covered by make)

Author: honno

Diff for: .circleci/config.yml

@@ -19,7 +19,6 @@ jobs:
           name: build docs
           no_output_timeout: 25m
           command: |
-            pip install .[doc]
             make
       - store_artifacts:
           path: _site/

Diff for: .github/workflows/pages.yml

@@ -73,11 +73,6 @@ jobs:
           python-version: '3.10.9'
           architecture: 'x64'
 
-      # Install dependencies:
-      - name: 'Install dependencies'
-        run: |
-          pip install .[doc]
-
       # Generate the documentation:
       - name: 'Build documentation'
         run: |