Re-land Use PyTorch RC release on release branch (#510) (#514)

Summary:
Currently the CI on release branch uses nightly PyTorch release. This PR changes it to use RC PyTorch release.

See the CI result for when the PR is landed (nightly channel): https://github.com/pytorch/data/runs/6867662390?check_suite_focus=true#step:8:3
See the CI result of the PR for release branch (test channel): https://github.com/pytorch/data/runs/6867788289?check_suite_focus=true#step:8:3

Pull Request resolved: #514

Reviewed By: NivekT

Differential Revision: D37116635

Pulled By: ejguan

fbshipit-source-id: 2dbe65da8121dfbd39690c83c2e1ca6cb70c0087

Author: ejguan

.github/workflows/ci.yml

@@ -4,6 +4,7 @@ on:
     branches:
       - main
       - release/*
+    tags:
   pull_request:
     types: [opened, synchronize, reopened, labeled]
     branches:
@@ -30,6 +31,16 @@ jobs:
           - 3.8
           - 3.9
     steps:
+      - name: Get PyTorch Channel
+        shell: bash
+        run: |
+          if [[ "${{ github.base_ref }}" == release/* ]] || [[ "${{ github.ref }}" == refs/heads/release/* ]] || [[ "${{ github.ref }}" == refs/tags/v* ]]; then
+            PT_CHANNEL="https://download.pytorch.org/whl/test/cpu/torch_test.html"
+          else
+            PT_CHANNEL="https://download.pytorch.org/whl/nightly/cpu/torch_nightly.html"
+          fi
+          echo "::set-output name=value::$PT_CHANNEL"
+        id: pytorch_channel
       - name: Setup additional system libraries
         if: startsWith( matrix.os, 'ubuntu' )
         run: |
@@ -55,7 +66,7 @@ jobs:
       - name: Install dependencies
         run: |
           pip3 install -r requirements.txt
-          pip3 install --pre torch -f https://download.pytorch.org/whl/nightly/cpu/torch_nightly.html
+          pip3 install --pre torch -f "${{ steps.pytorch_channel.outputs.value }}"
           pip3 install cmake ninja
           echo "/home/runner/.local/bin" >> $GITHUB_PATH
       - name: Build TorchData

.github/workflows/domain_ci.yml

@@ -9,7 +9,7 @@ on:
       - main
       # For PR created by ghstack
       - gh/*/*/base
-      - release/*
+      # - release/*
 
 jobs:
   torchvision: