use upload-artifacts v4

Author: FoamyGuy

.github/workflows/build-images.yml

@@ -16,7 +16,7 @@ jobs:
     - run: python3 -mpip install -r requirements.txt
     - run: git clone --depth=1 https://github.com/adafruit/Adafruit_Learning_System_Guides learn
     - run: env LEARN_GUIDE_REPO=learn/ python3 create_requirement_images.py
-    - uses: actions/upload-artifact@v2
+    - uses: actions/upload-artifact@v4
       with:
         name: images
         path: generated_images