rename license

The build we are doing will be COPYING.GPLv2 licensed. This renamed the license file so that it's called LICENSE for the dotnet-tool pack that occurs during deploy

.github/workflows/main.yml

@@ -58,6 +58,9 @@ jobs:
         with:
           submodules: recursive
 
+      - name: Rename License File
+        run: mv ./ffmpeg/COPYING.GPLv2 ./ffmpeg/LICENSE
+
       - name: Run CAKE
         run: dotnet run --project ./build/Build.csproj -- --target=Package --universalBinary=true --toolname=FFMpeg --executablename=ffmpeg --commandname=mgcb-ffmpeg --licensepath=ffmpeg/LICENSE
         env: