Adds automated job to cherry-pick commits from main (#580)

# Description

Adds an automated job to cherry-pick new commits from main to devel to
help keep the two branches in sync.


## Type of change

- New feature (non-breaking change which adds functionality)


## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [ ] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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---------
Signed-off-by: Kelly Guo <kellyguo123@hotmail.com>

.github/workflows/cherry-pick.yml

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+name: Cherry-pick from main to devel
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  cherry-pick:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0  # fetch full history to access other branches
+
+      - name: Set up Git config
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+
+      - name: Get latest commit SHA on main
+        id: get_commit
+        run: echo "::set-output name=sha::$(git rev-parse HEAD)"
+
+      - name: Checkout devel branch
+        run: git checkout devel
+
+      - name: Cherry-pick latest commit from main
+        run: |
+          git cherry-pick ${{ steps.get_commit.outputs.sha }}
+
+      - name: Push changes to devel
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          git push origin devel