test(e2e): add missing __init__.py to dashboards/ and entities/

The previous commit switched 6 files in these two directories from
absolute to relative imports, which exposed that both directories
were missing __init__.py. All 22 other workflows/ subdirs have one;
these two were outliers (likely why the absolute-import workaround
was used here in the first place).

Without __init__.py the dirs aren't proper Python packages, so
`from ...utilities.X` fails with `attempted relative import with no
known parent package` during pytest collection.

CI confirmed the issue: E2E Validation jobs failed on collection
for test_lifecycle.py, test_python_transform.py, and test_resources.py
in dashboards/ in run 26366784922.

Author: kingpanther13

tests/src/e2e/workflows/dashboards/__init__.py

@@ -0,0 +1 @@
+"""E2E tests for Home Assistant dashboard management tools."""

tests/src/e2e/workflows/entities/__init__.py

@@ -0,0 +1 @@
+"""E2E tests for Home Assistant entity management tools."""