ci: add package verification check (#66)

## Summary

Adds an end-to-end check that the built sdist and wheel install cleanly,
ship the expected sources and data files, and that `import apify_shared`
works — via the shared
[apify/workflows/python-package-check](apify/workflows#296)
action.

Wired into every PR via `_check_package.yaml`, and into both stable and
beta release workflows so the exact artifact about to hit PyPI is
verified first.

Author: vdusek

.github/workflows/_check_package.yaml

@@ -0,0 +1,36 @@
+name: Package check
+
+on:
+  # Runs when manually triggered from the GitHub UI.
+  workflow_dispatch:
+
+  # Runs when invoked by another workflow.
+  workflow_call:
+
+permissions:
+  contents: read
+
+jobs:
+  package_check:
+    name: Package check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Set up uv package manager
+        uses: astral-sh/setup-uv@v8.1.0
+        with:
+          python-version: "3.14"
+
+      - name: Build sdist and wheel
+        run: uv run poe build
+
+      - name: Verify built package
+        uses: apify/actions/python-package-check@v1.1.0
+        with:
+          package_name: apify_shared
+          dist_dir: dist
+          python_version: "3.14"
+          smoke_code: |
+            from apify_shared.consts import WebhookEventType

.github/workflows/manual_release_beta.yaml

@@ -60,6 +60,15 @@ jobs:
           version_number: ${{ needs.release_prepare.outputs.version_number }}
           ref: ${{ needs.changelog_update.outputs.changelog_commitish }}
 
+      - name: Verify built package
+        uses: apify/actions/python-package-check@v1.1.0
+        with:
+          package_name: apify_shared
+          dist_dir: dist
+          python_version: "3.14"
+          smoke_code: |
+            from apify_shared.consts import WebhookEventType
+
       # Publish the package to PyPI using PyPA official GitHub action with OIDC authentication.
       - name: Publish package to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1

.github/workflows/manual_release_stable.yaml

@@ -95,6 +95,15 @@ jobs:
           version_number: ${{ needs.release_prepare.outputs.version_number }}
           ref: ${{ needs.changelog_update.outputs.changelog_commitish }}
 
+      - name: Verify built package
+        uses: apify/actions/python-package-check@v1.1.0
+        with:
+          package_name: apify_shared
+          dist_dir: dist
+          python_version: "3.14"
+          smoke_code: |
+            from apify_shared.consts import WebhookEventType
+
       # Publishes the package to PyPI using PyPA official GitHub action with OIDC authentication.
       - name: Publish package to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1

.github/workflows/on_pull_request.yaml

@@ -17,6 +17,10 @@ jobs:
     name: Code checks
     uses: ./.github/workflows/_check_code.yaml
 
+  package_check:
+    name: Package check
+    uses: ./.github/workflows/_check_package.yaml
+
   tests:
     name: Tests
     uses: ./.github/workflows/_tests.yaml