Update github action dependencies

Signed-off-by: Travis F. Collins <[email protected]>

Author: tfcollins

.github/workflows/build.yml

@@ -59,7 +59,7 @@ jobs:
             cp *.mltbx toolbox
 
       - name: Save generated .mltbx file
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: TransceiverToolboxInstaller
           path: toolbox

.github/workflows/doc.yml

@@ -10,10 +10,10 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: recursive
-      - name: Set up Python 3.7
+      - name: Set up Python 3.9
         uses: actions/setup-python@v2
         with:
-          python-version: 3.7
+          python-version: 3.9
 
       - name: Set up MATLAB
         uses: matlab-actions/setup-matlab@v2