[ci] release action uses sub action for installing flutter

.github/workflows/release.yml

@@ -16,29 +16,13 @@ jobs:
       contents: write
     runs-on: ubuntu-latest
     steps:
-    - name: "Install Flutter"
-      # Github Actions don't support templates so it is hard to share this snippet with another action
-      # If we eventually need to use this in more workflow, we could create a shell script that contains this
-      # snippet.
-      #
-      # This uses a pinned version of Flutter rather than `stable` so that it is
-      # not subject to out-of-band failures when new releases happen. It does
-      # not use the auto-rolled pin because there's no way for the autoroller
-      # to test the actual release flow, so changes would still show up in
-      # post-submit. A manually-rolled pin means that any changes here must be
-      # made deliberately, so that the person updating it knows to watch the
-      # next actual auto-release to ensure that it works, and knows to revert
-      # the change if it doesn't.
-      run: |
-        cd $HOME
-        git clone https://github.com/flutter/flutter.git --depth 1 -b 3.38.1 _flutter
-        echo "$HOME/_flutter/bin" >> $GITHUB_PATH
-        cd $GITHUB_WORKSPACE
     # Checks out a copy of the repo.
     - name: Check out code
       uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
       with:
         fetch-depth: 0 # Fetch all history so the tool can get all the tags to determine version.
+    - name: "Install Flutter"
+      uses: ./.github/workflows/internals/install_flutter
     - name: Set up tools
       run: dart pub get
       working-directory: ${{ github.workspace }}/script/tool