Add nightly build and upload for torchcodec (#5814)

We want torchcodec's mac, cuda and cpu wheels to be automatically
uploaded to download.pytorch.org.

Currently we are building the wheels on every PR but not actually
uploading them as they are in dry-run mode. Example for cuda we do this:


https://github.com/pytorch/torchcodec/actions/runs/11485682426/job/31966672538?pr=272#step:10:97


![image](https://github.com/user-attachments/assets/d4fded9c-fe29-44b1-b3bc-2d9678bce10f)


@huydhn can you confirm that the dry-run is copying to the correct path
for this cuda wheel?

.github/workflows/trigger_nightly.yml

@@ -101,4 +101,11 @@ jobs:
           repository: pytorch/torchtune
           token: ${{ secrets.GH_PYTORCHBOT_TOKEN }}
           path: torchtune
-
+      - name: Trigger nightly torchcodec build
+        if: ${{ github.event_name == 'schedule' ||  inputs.domain == 'torchcodec' || inputs.domain == 'all' }}
+        uses: ./.github/actions/trigger-nightly
+        with:
+          ref: main
+          repository: pytorch/torchcodec
+          token: ${{ secrets.GH_PYTORCHBOT_TOKEN }}
+          path: torchcodec