Add missing items to integration test workflow path filter

For the sake of efficiency, the integration test workflow is configured to only be triggered on changes to relevant
files.

Recent changes to the project infrastructure introduced additional relevant files, but those were not added to the path
filter at that time.

Author: per1234

.github/workflows/test-integration.yml

@@ -5,13 +5,19 @@ on:
     paths:
       - '.github/workflows/test-integration.yml'
       - '.github/workflows/testdata/**'
+      - '.python-version'
+      - 'poetry.lock'
+      - 'pyproject.toml'
       - 'action.yml'
       - 'compilesketches/**'
 
   push:
     paths:
       - '.github/workflows/test-integration.yml'
       - '.github/workflows/testdata/**'
+      - '.python-version'
+      - 'poetry.lock'
+      - 'pyproject.toml'
       - 'action.yml'
       - 'compilesketches/**'