[ci] Enable the ruff rule requiring explicit encoding on text file I/O (#17897)

tests/unit_tests/analyze_memory/test_build_artifacts.py

@@ -22,7 +22,7 @@ def _make_build_dir(tmp_path: Path, name: str = "mydevice") -> Path:
 
 def _touch(path: Path) -> Path:
     path.parent.mkdir(parents=True, exist_ok=True)
-    path.write_text("")
+    path.write_text("", encoding="utf-8")
     return path
 
 

tests/unit_tests/test_compiled_config.py

@@ -74,13 +74,13 @@ def _write_storage(
         "framework": "arduino",
         "core_platform": core_platform,
     }
-    storage_path.write_text(json.dumps(data))
+    storage_path.write_text(json.dumps(data), encoding="utf-8")
 
 
 def _write_cache(cache_path: Path, body: str = _VALIDATED_CONFIG_YAML) -> Path:
     """Write the cache file and return it."""
     cache_path.parent.mkdir(parents=True, exist_ok=True)
-    cache_path.write_text(body)
+    cache_path.write_text(body, encoding="utf-8")
     return cache_path