fix(tracing): fix logic for setting in_app flag

Previously, in case packages added in `in_app_include` were installed
into a location outside of the project root directory, stack frames from
those packages were not marked as `in_app`. Cases include running Python
from virtualenv, created outside of the project root directory, or Python
packages installed into the system using package managers. This resulted
in inconsistency: traces from the same project would have different
`in_app` flags depending on the deployment method.

Steps to reproduce (virtualenv outside of project root):
```
$ docker run --replace --rm --name sentry-postgres -e POSTGRES_USER=sentry -e POSTGRES_PASSWORD=sentry -d -p 5432:5432 postgres
$ distrobox create -i ubuntu:24.04 -n sentry-test-in_app_include-venv
$ distrobox enter sentry-test-in_app_include-venv
$ python3 -m venv /tmp/.venv-test-in_app_include
$ source /tmp/.venv-test-in_app_include/bin/activate
$ pytest tests/integrations/django/test_db_query_data.py::test_query_source_with_in_app_include  # FAIL

```

Steps to reproduce (system packages):
```
$ docker run --replace --rm --name sentry-postgres -e POSTGRES_USER=sentry -e POSTGRES_PASSWORD=sentry -d -p 5432:5432 postgres
$ distrobox create -i ubuntu:24.04 -n sentry-test-in_app_include-os
$ distrobox enter sentry-test-in_app_include-os
$ sudo apt install python3-django python3-pytest python3-pytest-cov python3-pytest-django python3-jsonschema python3-urllib3 python3-certifi python3-werkzeug python3-psycopg2
$ pytest tests/integrations/django/test_db_query_data.py::test_query_source_with_in_app_include  # FAIL
```

In this change, the logic was slightly changed to avoid these
discrepancies and conform to the requirements, described in the PR with
`in_app` flag introduction:
getsentry#1894 (comment).
Note that the `_module_in_list` function returns `False` if `name` is
`None`, hence extra check before function call can be omitted to simplify
code.

sentry_sdk/tracing_utils.py

@@ -213,20 +213,16 @@ def add_query_source(span):
         is_sentry_sdk_frame = namespace is not None and namespace.startswith(
             "sentry_sdk."
         )
+        should_be_included = in_app_include and _module_in_list(
+            namespace, in_app_include
+        )
+        should_be_excluded = _is_external_source(abs_path) or (
+            in_app_exclude and _module_in_list(namespace, in_app_exclude)
+        )
 
-        should_be_included = not _is_external_source(abs_path)
-        if namespace is not None:
-            if in_app_exclude and _module_in_list(namespace, in_app_exclude):
-                should_be_included = False
-            if in_app_include and _module_in_list(namespace, in_app_include):
-                # in_app_include takes precedence over in_app_exclude, so doing it
-                # at the end
-                should_be_included = True
-
-        if (
-            abs_path.startswith(project_root)
-            and should_be_included
-            and not is_sentry_sdk_frame
+        if not is_sentry_sdk_frame and (
+            should_be_included
+            or (abs_path.startswith(project_root) and not should_be_excluded)
         ):
             break