ci: remove footprint ci workflow that has no effect

This workflow runs in the background and does not report anything and
does emit failures. Remove for now until we have something that is
actionable.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

.github/workflows/footprint.yml

@@ -1,73 +0,0 @@
-name: Footprint Delta
-
-on: pull_request
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  footprint-delta:
-    runs-on: zephyr-runner-linux-x64-4xlarge
-    if: github.repository == 'zephyrproject-rtos/zephyr'
-    container:
-      image: ghcr.io/zephyrproject-rtos/ci:v0.26.7
-      options: '--entrypoint /bin/bash'
-    strategy:
-      fail-fast: false
-    env:
-      ZEPHYR_TOOLCHAIN_VARIANT: zephyr
-    steps:
-      - name: Apply container owner mismatch workaround
-        run: |
-          # FIXME: The owner UID of the GITHUB_WORKSPACE directory may not
-          #        match the container user UID because of the way GitHub
-          #        Actions runner is implemented. Remove this workaround when
-          #        GitHub comes up with a fundamental fix for this problem.
-          git config --global --add safe.directory ${GITHUB_WORKSPACE}
-
-      - name: Update PATH for west
-        run: |
-          echo "$HOME/.local/bin" >> $GITHUB_PATH
-
-      - name: checkout
-        uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
-          fetch-depth: 0
-
-      - name: west setup
-        run: |
-          west init -l . || true
-          west config --global update.narrow true
-          west update 2>&1 1> west.update.log || west update 2>&1 1> west.update.log
-
-      - name: Detect Changes in Footprint
-        env:
-          BASE_REF: ${{ github.base_ref }}
-        run: |
-          export ZEPHYR_BASE=${PWD}
-          git config --global user.email "actions@zephyrproject.org"
-          git config --global user.name "Github Actions"
-          git remote -v
-          git rebase origin/${BASE_REF}
-          git checkout -b this_pr
-
-          export ZEPHYR_SDK_INSTALL_DIR=/opt/toolchains/zephyr-sdk-$( cat SDK_VERSION )
-
-          west update
-          west build -b frdm_k64f  tests/benchmarks/footprints -t ram_report
-          cp build/ram.json ram2.json
-          west build -b frdm_k64f  tests/benchmarks/footprints -t rom_report
-          cp build/rom.json rom2.json
-
-          git checkout origin/${BASE_REF}
-          west update
-          west build -p always -b frdm_k64f  tests/benchmarks/footprints -t ram_report
-          west build -b frdm_k64f  tests/benchmarks/footprints -t rom_report
-          cp build/ram.json ram1.json
-          cp build/rom.json rom1.json
-
-          git checkout this_pr
-          ./scripts/footprint/fpdiff.py ram1.json ram2.json
-          ./scripts/footprint/fpdiff.py rom1.json rom2.json