Upgrade CI (#658)

* version 2.6.0

* upgrade CI

Author: chaoming0625

.github/workflows/CI-models.yml

@@ -32,6 +32,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
+          python -m pip install --upgrade pip
           if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
           pip uninstall brainpy -y
           python setup.py install
@@ -79,6 +80,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
+        python -m pip install --upgrade pip
         if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
         pip uninstall brainpy -y
         python setup.py install
@@ -127,6 +129,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
+        python -m pip install --upgrade pip
         python -m pip install numpy>=1.21.0
         python -m pip install -r requirements-dev.txt
         python -m pip install tqdm brainpylib