Upgrade GitHub Actions to latest versions

Updated GitHub Actions to use newer versions of actions/checkout, actions/upload-artifact, and actions/download-artifact.

Author: zyclonite

.github/workflows/build.yml

@@ -27,7 +27,7 @@ jobs:
     runs-on: ${{ matrix.platform.runner }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Build Image
         run: buildah bud --platform ${{ matrix.platform.name }} -f ./Dockerfile -t ${{ env.IMAGE_NAME }}:${{ matrix.platform.tag }} .
@@ -42,7 +42,7 @@ jobs:
         run: podman save -o /tmp/image.tar ${{ env.IMAGE_NAME }}:${{ matrix.platform.tag }}
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: image-${{ matrix.platform.tag }}
           path: /tmp/image.tar
@@ -54,7 +54,7 @@ jobs:
     environment: production
     steps:
       - name: Download artifacts
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
 
       - name: Import images
         run: |