Fix and update doc deployment (#3495)

Summary:
- Fix condition to add new commit to gh-pages
- Allow to deploy docs from workflow dispatch

Pull Request resolved: https://github.com/pytorch/audio/pull/3495

Differential Revision: D47767443

Pulled By: mthrok

fbshipit-source-id: 9ca858868f3e822e532c21cde9d7499af9891a51

.github/workflows/build_docs.yml

@@ -4,7 +4,6 @@ on:
   pull_request:
   push:
     branches:
-      - nightly
       - main
       - release/*
     tags:
@@ -35,13 +34,14 @@ jobs:
         export PYTHON_VERSION="${{ matrix.python_version }}"
         export CU_VERSION="${{ matrix.cuda_arch_version }}"
         export CUDATOOLKIT="pytorch-cuda=${CU_VERSION}"
-        export BUILD_VERSION="$( cut -f 1 -d a version.txt )".dev"$(date "+%Y%m%d")"
 
         # Set CHANNEL
         if [[(${GITHUB_EVENT_NAME} = 'pull_request' && (${GITHUB_BASE_REF} = 'release'*)) || (${GITHUB_REF} = 'refs/heads/release'*) ]]; then
           export CHANNEL=test
+          export BUILD_VERSION="$( cut -f 1 -d a version.txt )"
         else
           export CHANNEL=nightly
+          export BUILD_VERSION="$( cut -f 1 -d a version.txt )".dev"$(date "+%Y%m%d")"
         fi
 
         echo "::group::Create conda env"
@@ -88,8 +88,8 @@ jobs:
         cp -rf docs/build/html/* "${RUNNER_DOCS_DIR}"
         mv docs/build/html /artifacts/
 
-  commit:
-    if: ${{ (github.repository == 'pytorch/audio') && ((github.event_name == 'push') && (github.ref_name == 'nightly')) }}
+  commit-main:
+    if: ${{ (github.repository == 'pytorch/audio') && (github.ref_name == 'main') }}
     permissions:
       # Required for `git push`
       # Note:
@@ -107,7 +107,7 @@ jobs:
     - uses: actions/download-artifact@v3
       with:
         name: docs
-    - name: Update nightly doc
+    - name: Update main doc
       run: |
         set -x
 
@@ -116,7 +116,7 @@ jobs:
         # When `git clone`, `gh-pages` branch is fetched by default.
         # The size of gh-pages grows significantly, so we use ammend and force push
         # We add a new commit once a week
-        if [ "date +%u" = "1" ]; then
+        if [ "$(date +%d)" = "1" ]; then
            git commit --allow-empty -m "placeholder"
         fi