Nightly Release of Torch-MLIR python wheels for linux_x86_64 builds (#1)

Reuses [build_linux_packages.sh](https://github.com/llvm/torch-mlir/blob/main/build_tools/python_deploy/build_linux_packages.sh) script to build the project and generate python wheels. I however chose to not port the original github actions workflows for snapshot releases, which seemed to do a lot more than what I initially wanted. Here's what's roughly different in this trimmed down version:
- html patching for hosting pip wheels is no longer used - instead went with the [expand_assets trick](https://fzakaria.com/2024/01/15/abusing-github-as-a-pypi-server.html), similar to [openxla/stablehlo](https://github.com/openxla/stablehlo/blob/main/.github/workflows/publishWheelRelease.yml)
- only release linux x86_64 prebuilt wheels (not macos, windows, aarch64 builds) - this may be updated later by interested parties

I used a standalone fork which was useful for the initial bringup - it took a good 30-ish iterations on `main` branch to nail the github workflow right, and some playing with auth tokens. 

Here's how the release page looks like:
- https://github.com/sjain-stanford/torch-mlir-release/releases
- https://github.com/sjain-stanford/torch-mlir-release/releases/expanded_assets/dev-wheels
(it follows the same naming convention as existing wheels, but updates the same `dev-wheels` release in place to avoid changing the expand_assets link required for pip-style hosting)

Here's the workflow: 
- https://github.com/sjain-stanford/torch-mlir-release/actions/runs/7825872338

@stellaraccident and I took a call to avoid using Personal Access Tokens (PAT) here for release permissions, and instead elevating permissions on [GITHUB_TOKEN](https://docs.github.com/en/actions/security-guides/automatic-token-authentication#modifying-the-permissions-for-the-github_token) for `contents` scope (required for an action to make a release). We think this is reasonable considering this repo is locked down in terms of number of contributors with write access, and that this is scope specific and not a write-all.

Author: sjain-stanford

.github/actions/setup-build/action.yml

@@ -0,0 +1,19 @@
+name: "Setup build environment"
+description: "Setup python, ninja-build etc."
+
+# Make top-level permissions on GITHUB_TOKEN more restrictive
+permissions:
+  contents: read
+
+runs:
+  using: "composite"
+
+  steps:
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.11'
+
+    - name: Install prerequisites (Linux)
+      run: sudo apt-get install --yes ninja-build
+      shell: bash

.github/workflows/buildReleaseAndPublish.yml

@@ -0,0 +1,73 @@
+name: Build Release and Publish
+
+on:
+  workflow_dispatch:
+  schedule:
+  # Runs at 11:00 AM UTC, which is 3:00 AM PST (UTC-8)
+   - cron: '0 11 * * *'
+
+# Ensure that only a single job or workflow using the same
+# concurrency group will run at a time. This would cancel
+# any in-progress jobs in the same github workflow and github
+# ref (e.g. refs/heads/main or refs/pull/<pr_number>/merge).
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build_linux:
+    name: Linux x86_64 Build
+    runs-on: ubuntu-latest
+    # Elevates permissions for `GITHUB_TOKEN`'s content scope (to allow this action to make a release)
+    permissions:
+      contents: write
+    # Don't run this in everyone's forks.
+    if: github.repository == 'llvm/torch-mlir-release'
+    strategy:
+      matrix:
+        package: [torch-mlir]
+        py_version: [cp310-cp310, cp311-cp311]
+
+    steps:
+      - name: Checkout torch-mlir
+        uses: actions/checkout@v4
+        with:
+          repository: llvm/torch-mlir
+          ref: refs/heads/main
+          submodules: 'true'
+
+      - name: Setup workspace
+        uses: ./.github/actions/setup-build
+
+      - name: Build Python wheels and smoke test
+        run: |
+          cd $GITHUB_WORKSPACE
+          tm_package_version="$(printf '%(%Y%m%d)T.${{ github.run_number }}')"
+          echo "tm_package_version=${tm_package_version}" >> $GITHUB_ENV
+          printf "TORCH_MLIR_PYTHON_PACKAGE_VERSION=%s\n" ${tm_package_version} > ./torch_mlir_package_version
+          TM_PYTHON_VERSIONS=${{ matrix.py_version }} TM_PACKAGES=${{ matrix.package }} ./build_tools/python_deploy/build_linux_packages.sh
+
+      - name: Make assets available in dist
+        run: |
+          mkdir dist
+          cp build_tools/python_deploy/wheelhouse/torch*.whl dist/
+
+      - name: Upload python wheels
+        uses: actions/upload-artifact@v4
+        with:
+          if-no-files-found: error
+          name: snapshot-${{ matrix.package }}-${{ matrix.py_version }}-${{ env.tm_package_version }}
+          path: dist
+
+      - name: Release python wheels
+        uses: ncipollo/[email protected]
+        with:
+          artifacts: dist/*.whl
+          token: "${{ secrets.GITHUB_TOKEN }}"
+          tag: "dev-wheels"
+          name: "dev-wheels"
+          body: "Automatic snapshot release of torch-mlir python wheels."
+          removeArtifacts: false
+          allowUpdates: true
+          replacesArtifacts: true
+          makeLatest: true