ci: fix up testing of python code

Using pull_request_target causes us to run code tests against main since
that's the default code checked out. Don't depend on pyproject.toml
configuring pytest to generate code coverage by always specifying the
flag.

.github/workflows/code-test.yaml

@@ -7,7 +7,7 @@ on:
     paths:
       - "python/**"
       - ".github/workflows/code-test.yaml"
-  pull_request_target:
+  pull_request:
     paths:
       - "python/**"
       - ".github/workflows/code-test.yaml"
@@ -45,7 +45,7 @@ jobs:
           cache: "poetry"
       - run: poetry install --sync --with test
       - run: poetry build
-      - run: "poetry run pytest --cov-report xml:coverage.xml"
+      - run: "poetry run pytest --cov --cov-report xml:coverage.xml"
       - uses: orgoro/coverage@3f13a558c5af7376496aa4848bf0224aead366ac # v3.2
         with:
           coverageFile: python/${{ matrix.project }}/coverage.xml