add github action to sync generation branch to future branch (#25019)

.github/workflows/sync-generation-to-future.yml

@@ -0,0 +1,54 @@
+name: sync-generation
+run-name: Sync commit from generation to future - temporary
+env:
+  GH_TOKEN: ${{ github.token }}
+on:
+  push:
+    branches:
+      - 'generation'
+jobs:
+  sync_generation:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+    - uses: actions/setup-node@v4
+      with:
+        node-version: 14.17.1
+    - run: npm install -g autorest@latest
+    - uses: actions/checkout@v4
+      with:
+        ref: 'future'
+    - name: sync generation
+      shell: pwsh
+      run: |
+        Install-Module -Name PowerShellGet -RequiredVersion 2.2.3 -Force;
+        Install-Module -Name platyPS -RequiredVersion 0.14.2 -Force;
+
+        git config user.email "[email protected]";
+        git config user.name "azure-powershell-bot";
+        $commitId = '${{ github.sha }}'
+        $repoRoot = '${{ github.workspace }}'
+
+        git fetch origin generation
+        git cherry-pick $commitId --strategy-option theirs
+        git reset HEAD~1
+        <#
+          calculate changed modules
+        #>
+        $modulePaths = @()
+        git status --short | Where-Object { $_ -match ".*src.*" } | ForEach-Object { $modulePaths += $_.substring($_.IndexOf("src"), $_.IndexOf(".Autorest")+6) }
+        if (0 -eq $modulePaths.Count) {
+          return
+        }
+        $modulePaths | Select-Object -Unique
+        foreach ($modulePath in $modulePaths) {
+          $modulePath = Join-Path $repoRoot $modulePath
+          Set-Location $modulePath
+          autorest --max-memory-size=8192
+          ./build-module.ps1
+        }
+        Set-Location $repoRoot
+        git add src
+        git commit -m "cherry-pick $commitId from generation"
+        git push origin future