feat: move to ESM only (#4)

Moves to ESM only instead of shipping a dual package. We will continue
maintaining a v1 branch in case bug fixes are needed.

.github/workflows/main.yml

@@ -14,9 +14,9 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Use Node v${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - name: Install Dependencies

.github/workflows/publish.yml

@@ -0,0 +1,49 @@
+name: Publish Release (npm)
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+      - name: Install Dependencies
+        run: npm ci
+      - name: Lint
+        run: npm run lint
+      - name: Build
+        run: npm run build
+      - name: Test
+        run: npm test
+
+  publish-npm:
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22.x
+          registry-url: 'https://registry.npmjs.org'
+          cache: 'npm'
+      - run: npm ci
+      - run: npm version ${TAG_NAME} --git-tag-version=false
+        env:
+          TAG_NAME: ${{ github.ref_name }}
+      - run: npm publish --provenance --access public --tag next
+        if: "github.event.release.prerelease"
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.npm_token }}
+      - run: npm publish --provenance --access public
+        if: "!github.event.release.prerelease"
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.npm_token }}