workflow for updating flutter candidate (#6034)

![](https://media.giphy.com/media/v1.Y2lkPTc5MGI3NjExdjdjbjRkaGFhZHplNzUwd241Y2x4aTh4N2Zqdzk1aWRncHlvcGJtOCZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/11lz62kfEmsM00/giphy.gif)

This PR creates a workflow that will run daily to update the flutter-candidate.txt file. The objective of this is to have a daily resolution for flutter candidate versions, so in the future we know what version to use with legacy devtools versions.

Example of what the PR will look like.
#6037

Fixes #6024

.github/workflows/daily-dev-bump.yaml

@@ -45,8 +45,6 @@ jobs:
       - name: setup git config
         run: |
 
-          # TODO(https://github.com/flutter/devtools/issues/4949):  Change the author to
-          # a flutter owned account
           git config user.name "DevTools Workflow Bot"
           git config user.email "[email protected]"
 

.github/workflows/flutter-candidate-update.yaml

@@ -0,0 +1,68 @@
+name: Flutter Candidate Update
+on:
+  workflow_dispatch: # Allows for manual triggering if needed
+  schedule:
+    # * is a special character in YAML so you have to quote this string
+    - cron: "0 8 * * *" # Run every day at midnight Pacific Time
+
+permissions:
+  contents: write
+  pull-requests: write
+
+env:
+  GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+jobs:
+  update-candidate:
+    name: Update Flutter Candidate Version
+    runs-on: ubuntu-latest
+    steps:
+      - name: git clone devtools
+        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9
+        with:
+          ref: master
+
+      - uses: dart-lang/setup-dart@d6a63dab3335f427404425de0fbfed4686d93c4f
+
+      - name: setup git config
+        run: |
+
+          git config user.name "DevTools Workflow Bot"
+          git config user.email "[email protected]"
+
+      - name: get the latest flutter candidate
+        run: |
+          set -ex
+          pushd tool/
+          dart pub get
+          popd
+
+          tool/latest_flutter_candidate.sh | sed 's|refs/tags/||' > flutter-candidate.txt
+
+      - name: Create the PR
+        run: |
+          set -ex
+          if ! [[ `git status --porcelain --untracked-files=no` ]]; then
+            # No changes made, so we can just exit.
+            echo "No change to the flutter-candidate.txt file"
+            exit
+          fi
+          COMMIT_MESSAGE="Changing Flutter Candidate to $(cat flutter-candidate.txt)"
+          BRANCH_NAME="auto-candidate-$(date +%s)"
+          # Stage the file, commit and push
+          git checkout -b "$BRANCH_NAME"
+          git add .
+          git commit -m "$COMMIT_MESSAGE"
+          git push -u origin "$BRANCH_NAME"
+
+
+          PR_URL=$(gh pr create --title "$COMMIT_MESSAGE" --body "Automated Flutter candidate version bump.") 
+
+          # Change github credentials back to the actions bot.
+          GH_TOKEN="$ORIGINAL_GH_TOKEN"
+
+          gh pr edit $PR_URL --add-label "autosubmit"
+
+        env:
+          GH_TOKEN: ${{ secrets.DEVTOOLS_WORKFLOW_BOT_TOKEN }}
+          ORIGINAL_GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

flutter-candidate.txt

@@ -0,0 +1 @@
+3.13.0-2.0.pre