Run tasks-gen scripts automatically (#964)

This PR adds a Github Action to automatically run the
`@huggingface/tasks-gen` scripts and open a PR if anything has changed.
The workflow is triggered once a day (3am) and can be triggered manually
if needed.

Here is an example of auto-generated PR:
#1030.

---

Note: lint issues seems unrelated. But it doesn't seem to happen on main
(see
[here](https://github.com/huggingface/huggingface.js/actions/workflows/lint.yml?query=branch%3Amain))
so I don't know what's causing it 😕

---------

Co-authored-by: Pauline Bailly-Masson <[email protected]>

Author: Wauplin

.github/workflows/update-specs.yml

@@ -0,0 +1,63 @@
+name: Tasks - Update specs
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "0 3 * * *" # Every day at 3am
+
+concurrency:
+  group: update-specs
+  cancel-in-progress: true
+
+defaults:
+  run:
+    working-directory: packages/tasks-gen
+
+jobs:
+  pull_request:
+    runs-on: ubuntu-latest
+    steps:
+      # Setup
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: "20"
+      - name: Install pnpm
+        uses: pnpm/action-setup@v2
+        with:
+          run_install: true
+
+      # Generate specs
+      - run: pnpm run inference-tgi-import
+      - run: pnpm run inference-tei-import
+      - run: pnpm run inference-codegen
+
+      # Check changes
+      - run: git status
+
+      # Create or update Pull Request
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v7
+        with:
+          token: ${{ secrets.TOKEN_INFERENCE_SYNC_BOT }}
+          commit-message: Update tasks specs (automated commit)
+          branch: update-tasks-specs-automated-pr
+          delete-branch: true
+          title: "[Bot] Update tasks specs"
+          body: |
+            This PR updates the @huggingface/tasks specs. It has been generated by running:
+            ```sh
+            pnpm run inference-tgi-import
+            pnpm run inference-tei-import
+            pnpm run inference-codegen
+            ```
+
+            This PR was automatically created by the [Tasks - Update specs workflow](https://github.com/huggingface/huggingface.js/blob/main/.github/update-specs.yml).
+
+            Make sure the changes are correct before merging.
+          labels: |
+            tasks
+            specs
+          reviewers: |
+            Wauplin
+            hanouticelina