Add workflow stub for installation testing

Author: jhamon

.github/workflows/testing-install.yaml

@@ -0,0 +1,44 @@
+name: Installation Tests
+
+on:
+  workflow_call:
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  test-install:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+        python: [3.9]
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+
+      - name: Install build tools
+        run: |
+          python -m pip install --upgrade pip setuptools wheel build
+
+      - name: Build sdist & wheel
+        run: python -m build --sdist --wheel
+
+      - name: Install from built artifacts
+        run: |
+          # Use the wheel if it's pure-python; fallback to sdist otherwise
+          pip install dist/*.whl || pip install dist/*.tar.gz
+
+      - name: Verify import & version
+        run: |
+          python - <<EOF
+          import pinecone
+          print("Imported OK, version:", pinecone.__version__)
+          EOF