Update actions in CI to silence warnings in workflow logs

Author: noritada

.github/workflows/build-conda.yml

@@ -21,7 +21,7 @@ jobs:
           - os: macos-latest  
             platform: x32
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Setup Conda
       uses: s-weigand/setup-conda@v1

.github/workflows/build-windows.yml

@@ -21,7 +21,7 @@ jobs:
           - os: macos-latest  
             platform: x32
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Setup Conda
       uses: s-weigand/setup-conda@v1

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
         python-version: ["3.9"]
     steps:
 
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4