Upgrade action versions

Author: WyattBlue

.github/workflows/build-ffmpeg.yml

@@ -41,8 +41,8 @@ jobs:
       run:
         shell: ${{ matrix.shell }}
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
       - name: Set deployment target
@@ -78,7 +78,7 @@ jobs:
           cibuildwheel --output-dir output
           rm -f output/*.whl
       - name: Upload FFmpeg
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: output-${{ matrix.os }}-${{ matrix.arch }}
           path: output/