tests: Fix pytest-homeassistant-custom-component to 0.13.254

Until HA announces what they have done in 2025.7 beta to break test
frameworks, stick with the last 2025.6.x version.

requirements-dev.txt

@@ -1,6 +1,6 @@
 fuzzywuzzy
 levenshtein
-pytest-homeassistant-custom-component~=0.13.221
+pytest-homeassistant-custom-component=0.13.254
 pytest
 pytest-asyncio
 pytest-cov