CI: try fix missing pip step by separate job step

.github/workflows/main.yml

@@ -104,9 +104,12 @@ jobs:
         with:
           python-version: ${{ matrix.ver.py }}
 
-      - name: Install dependencies
+      - name: Update pip
         run: |
           python -m pip install --upgrade pip
+
+      - name: Install dependencies
+        run: |
           python -m pip install build coveralls>=3.0.0 numpy${{ matrix.ver.np }}
 
       - name: bleeding edge