docs(turbopack): build, deploy rustdocs (#7342)

### Description

This PR sets up daily CI workflow to deploy docs to
https://turbopack-rust-docs.vercel.sh/.

It currently uses vercel ci to deploy instead of git integration, for
couple of reasons

- we need to build cross-repo docs (next.js  / turbopack)
- I didn't want to accidentally disrupt existing deploy connection in
this repo / next.js repo

This is to get things started; we can / will definitely improve
deployment over time.

### Testing Instructions

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  Give a quick description of steps to test your changes.
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Closes PACK-2375

Author: kwonoj

.github/workflows/turbopack-nightly-rustdocs-deploy.yml

@@ -0,0 +1,75 @@
+name: Turbopack Nightly Release
+
+on:
+  schedule:
+    - cron: "15 8 * * *" # Run every day at 00:15 PST
+  workflow_dispatch:
+    inputs:
+      version:
+        description: Turbopack (Next.js) version, sha, branch to generate docs
+        type: string
+        default: "canary"
+      prod:
+        description: Deploy docs to production
+        type: boolean
+        default: false
+
+jobs:
+  # deploy turbopack-specific packages' rustdoc documentation.
+  turbopack_deploy_rustdocs:
+    name: Deploy Turbopack rustdocs
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    if: github.repository_owner == 'vercel'
+    env:
+      TURBOPACK_RUST_DOCS_VERCEL_CLI_DEPLOY: ${{ secrets.TURBOPACK_RUST_DOCS_VERCEL_CLI_DEPLOY }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Find Next.js latest release version
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          # Grab the latest release version from next.js repo, including prelease. `/releases/latest` will only return latest stable release.
+          echo NEXJS_LATEST_VERSION=$(gh release --repo vercel/next.js --limit 1 list | sed -n 1p | awk '{print $1}') >> $GITHUB_ENV
+
+      - name: Set Next.js release version
+        run: |
+          echo "NEXTJS_VERSION=${{ inputs.version != '' && inputs.version || env.NEXJS_LATEST_VERSION }}" >> $GITHUB_ENV
+
+      - name: Print Next.js release version to checkout
+        run: echo "Checking out Next.js ${{ env.NEXTJS_VERSION }}"
+
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          repository: vercel/next.js
+          path: nextjs_upstream
+
+      - uses: ./.github/actions/setup-node
+
+      - name: Setup Rust
+        uses: ./.github/actions/setup-rust
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+
+      - name: Build rustdoc
+        run: |
+          # Temporary index page
+          printf "# Turbopack \n\nWelcome to an overview of the Turbopack documentation.\nCurrently it's work in progress, the only package available is [Turbo tasks-fs](turbo_tasks_fs/index.html)" > index.md
+          RUSTDOCFLAGS="-Z unstable-options --index-page $(pwd)/index.md" cargo doc --manifest-path ./nextjs_upstream/Cargo.toml --target-dir out_docs -p turbo-tasks-fs --no-deps
+
+      - name: Link project
+        run: |
+          npx vercel link --cwd ./out_docs/doc --project turbopack-rust-docs --token=$TURBOPACK_RUST_DOCS_VERCEL_CLI_DEPLOY --scope=vercel --yes
+
+      - name: Trigger deploy
+        if: ${{ github.ref != 'refs/heads/main' || !inputs.prod }}
+        run: |
+          npx vercel deploy --cwd ./out_docs/doc --token=$TURBOPACK_RUST_DOCS_VERCEL_CLI_DEPLOY --scope=vercel --yes
+
+      - name: Trigger deploy (prod)
+        if: ${{ github.ref == 'refs/heads/main' || inputs.prod }}
+        run: |
+          npx vercel deploy --cwd ./out_docs/doc --token=$TURBOPACK_RUST_DOCS_VERCEL_CLI_DEPLOY --scope=vercel --prod --yes

Cargo.lock

@@ -256,7 +256,7 @@ serde_qs = "0.11.0"
 serde_with = "2.3.2"
 serde_yaml = "0.9.17"
 sha2 = "0.10.6"
-smallvec = { version = "1.11.1", features = [
+smallvec = { version = "1.13.1", features = [
   "serde",
   "const_generics",
   "union",

Cargo.toml

@@ -33,7 +33,7 @@ turbopack-ecmascript = { workspace = true }
 turbopack-swc-utils = { workspace = true }
 
 parcel_sourcemap = "2.1.1"
-smallvec = "1.11.0"
+smallvec = { workspace = true }
 swc_core = { workspace = true, features = [
   "css_ast",
   "css_codegen",