update actions

Author: srmnitc

.github/workflows/testing.yml

@@ -18,9 +18,9 @@ jobs:
             label: linux-64-py-3-9
             prefix: /usr/share/miniconda3/envs/my-env
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Setup Mambaforge
-      uses: conda-incubator/setup-miniconda@v2
+      uses: conda-incubator/setup-miniconda@v3
       with:
           python-version: ${{ matrix.python-version }}
           miniforge-variant: Mambaforge