ci: switch Yarn to Bun

* For this project, it's faster to Bun install without a cache than to restore a cache using Yarn.
* For the publish workflow, we still need the `setup-node` action. It uses the npm CLI to publish the package to NPM with provenance.

.github/workflows/ci.yml

@@ -17,21 +17,18 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-
-      - uses: actions/cache@v4
-        id: yarn-cache
+      - uses: oven-sh/setup-bun@v1
         with:
-          path: "**/node_modules"
-          key: ${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
+          bun-version: 1.1.3
 
       - name: Install dependencies
-        run: yarn install
+        run: bun install --no-scripts
 
       - name: Build the library
-        run: yarn build
+        run: bun run build
 
       - name: Run unit tests
-        run: yarn test
+        run: bun test
 
       # Only trigger deploy if previous steps pass and branch is main
       - name: Deploy docs

.github/workflows/publish-to-npm.yml

@@ -15,16 +15,22 @@ jobs:
       id-token: write
     steps:
       - uses: actions/checkout@v4
+
+      # The Node.js action is required to use npm.
       - uses: actions/setup-node@v4
         with:
           node-version: "20.x"
           registry-url: "https://registry.npmjs.org"
 
+      - uses: oven-sh/setup-bun@v1
+        with:
+          bun-version: 1.1.3
+
       - name: Install dependencies
-        run: yarn install
+        run: bun install --no-scripts
 
       - name: Build package
-        run: yarn build
+        run: bun run build
 
       - name: Publish package
         env: