feat: add PR validation workflow (#365)

.github/workflows/pr-validation.yaml

@@ -0,0 +1,37 @@
+name: PR Validation
+
+on:
+  pull_request:
+    paths-ignore:
+      - .speakeasy/in.openapi.yaml
+
+concurrency:
+  group: pr-validation-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+        with:
+          enable-cache: true
+
+      - name: Build SDK
+        run: uv build
+
+      - name: Type check (mypy)
+        run: uv run --group dev mypy src
+
+      - name: Type check (pyright)
+        run: uv run --group dev pyright src
+
+      - name: Lint (pylint)
+        run: uv run --group dev pylint src --rcfile pylintrc