Update ci.yml

.github/workflows/ci.yml

@@ -2,19 +2,27 @@ name: CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   build:
-    runs-on: Ubuntu 22.04.5
+    runs-on: ubuntu-latest
+
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
+      with:
+        python-version: '3.9'
+    - name: Cache dependencies
+      uses: actions/cache@v3
       with:
-        python-version: 3.8
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip