Removes unused pipelines (#3990)

# Description

Removes unused pipelines for cleaner code

.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

.github/workflows/mirror-repository.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: Mirror Repository
-
-on:
-  push:
-    branches:
-      - main
-
-# Concurrency control to prevent parallel runs
-concurrency:
-  group: mirror-repository-${{ github.ref }}
-  cancel-in-progress: true
-
-permissions:
-  contents: write
-
-jobs:
-  mirror-repository:
-    runs-on: ubuntu-latest
-    timeout-minutes: 30
-    # Only run on specific repository
-    if: github.repository == 'isaac-sim/IsaacLab'
-    environment:
-      name: mirror-production
-      url: https://github.com/${{ vars.TARGET_REPO }}
-
-    steps:
-    - name: Install Git LFS
-      run: |
-        curl -s https://packagecloud.io/install/repositories/github/git-lfs/script.deb.sh | sudo bash
-        sudo apt-get install git-lfs
-        git lfs install
-
-    - name: Checkout Code
-      uses: actions/checkout@v4
-      with:
-        fetch-depth: 0
-        lfs: true
-
-    - name: Configure Git
-      run: |
-        git config --global user.name "Isaac LAB CI Bot"
-        git config --global user.email "isaac-lab-ci-bot@nvidia.com"
-
-    - name: Set Target Repository URL
-      run: |
-        echo "TARGET_REPO=${{ vars.TARGET_REPO }}" >> $GITHUB_ENV
-        echo "TARGET_BRANCH=${{ vars.TARGET_BRANCH || 'main' }}" >> $GITHUB_ENV
-
-    - name: Mirror to Target Repository
-      run: |
-        # Remove existing target remote if it exists
-        git remote remove target 2>/dev/null || true
-
-        # Add target remote with authentication
-        git remote add target https://${{ secrets.GH_TOKEN }}@github.com/${TARGET_REPO}.git
-
-        # Fetch latest from target to avoid conflicts
-        git fetch target $TARGET_BRANCH 2>/dev/null || true
-
-        # Push to target repository and branch (source is always main)
-        git push --force target main:$TARGET_BRANCH
-
-        echo "✅ Successfully mirrored main to ${TARGET_REPO}:$TARGET_BRANCH"