Split staging release script into 2 parts (#6339)

Author: hsubox76

.github/workflows/release-log.yml

@@ -4,7 +4,7 @@ on:
   pull_request:
     branches:
       - release
-      - v8-releasebranch
+      - '*-releasebranch'
 
 jobs:
   release:

.github/workflows/release-pr.yml

@@ -0,0 +1,39 @@
+name: Create Release PR
+
+on:
+  push:
+    branches:
+      - release
+      - '*-releasebranch'
+
+jobs:
+  release:
+    name: Create Release PR
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@master
+        with:
+          # This makes Actions fetch all Git history so that Changesets can generate changelogs with the correct commits
+          fetch-depth: 0
+
+      - name: Setup Node.js 14.x
+        uses: actions/setup-node@master
+        with:
+          node-version: 14.x
+
+      - name: Install Dependencies
+        run: yarn
+
+      # Ensures a new @firebase/app is published with every release.
+      # This keeps the SDK_VERSION variable up to date.
+      - name: Add a changeset for @firebase/app
+        # pull master so changeset can diff against it
+        run: |
+          git pull -f --no-rebase origin master:master
+          yarn ts-node-script scripts/ci/add_changeset.ts
+
+      - name: Create Release Pull Request
+        uses: changesets/action@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.OSS_BOT_GITHUB_TOKEN }}

.github/workflows/release-staging.yml

@@ -30,35 +30,20 @@ jobs:
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}
         script: |
+          let branch = context.ref.replace("refs/heads/", "")
           await github.rest.repos.merge({
             owner: context.repo.owner,
             repo: context.repo.repo,
-            base: 'release',
+            base: branch,
             head: 'master'
           })
-    - name: Checkout release branch (with history)
+    - name: Checkout current branch (with history)
       uses: actions/checkout@master
       with:
         # Release script requires git history and tags.
         fetch-depth: 0
-        ref: release
     - name: Yarn install
       run: yarn
-    # Ensures a new @firebase/app is published with every release.
-    # This keeps the SDK_VERSION variable up to date.
-    - name: Add a changeset for @firebase/app
-      # pull master so changeset can diff against it
-      run: |
-        git pull -f --no-rebase origin master:master
-        yarn ts-node-script scripts/ci/add_changeset.ts
-    - name: Create Release Pull Request
-      uses: changesets/action@v1
-      env:
-        GITHUB_TOKEN: ${{ secrets.OSS_BOT_GITHUB_TOKEN }}
-    - name: Go back to release branch
-      # changesets/action created and checked out a new branch
-      # return to `release` branch.
-      run: git checkout release
     - name: Publish to NPM
       # --skipTests No need to run tests
       # --skipReinstall Yarn install has already been run