More CI cleanup, add style workflow (#107)

- Changes on the `test.yml` workflow:
  - Using poetry instead of pip. Contrary to what I wrote in #75, it is possible to use poetry (and have the benefits of shorter install times) without the need for having two separate versions of `pyproject.toml` and `poetry.lock`.
  - Reduce the trigger scope to only run when files in these directories are modified:
    - `lerobot/`
    - `tests/`
    - `examples/`
    - `.github/`
- Add `style.yml` workflow for doing a `ruff check` pass on the code
- More cleanup (removed deprecated workflow)

.github/workflows/nightly-tests.yml

@@ -1,6 +1,6 @@
 # Inspired by
 # https://github.com/huggingface/peft/blob/main/.github/workflows/nightly.yml
-name: Nightly Tests
+name: Nightly
 
 on:
   workflow_dispatch:
@@ -11,7 +11,6 @@ env:
   DATA_DIR: tests/data
   # SLACK_API_TOKEN: ${{ secrets.SLACK_API_TOKEN }}
 
-
 jobs:
   run_all_tests_cpu:
     name: "Test CPU"
@@ -33,11 +32,13 @@ jobs:
         env:
           DATA_DIR: tests/data
         run: pytest -v --cov=./lerobot --disable-warnings tests
+
       - name: Tests end-to-end
         env:
           DATA_DIR: tests/data
         run: make test-end-to-end
 
+
   run_all_tests_single_gpu:
     name: "Test GPU"
     strategy:
@@ -59,6 +60,7 @@ jobs:
     steps:
       - name: Nvidia-smi
         run: nvidia-smi
+
       - name: Test
         run: pytest -v --cov=./lerobot --cov-report=xml --disable-warnings tests
       #   TODO(aliberts): Link with HF Codecov account
@@ -69,14 +71,6 @@ jobs:
       #     verbose: true
       - name: Tests end-to-end
         run: make test-end-to-end
-      - name: Tailscale Wait
-        if: ${{ failure() || runner.debug == '1' }}
-        uses: huggingface/tailscale-action@v1
-        with:
-           waitForSSH: true
-           authkey: ${{ secrets.TAILSCALE_SSH_AUTHKEY }}
-           slackChannel: ${{ secrets.SLACK_CIFEEDBACK_CHANNEL }}
-           slackToken: ${{ secrets.SLACK_CIFEEDBACK_BOT_TOKEN }}
 
     #   - name: Generate Report
     #     if: always()