add explicit UTF-8 encoding

tasks/customjson.py

@@ -32,7 +32,7 @@ class CustomJSON(Task):
             print("-" * 80)
 
         else:
-            with open(filepath, 'r') as f:
+            with open(filepath, 'r', encoding='utf-8') as f:
                 for line in f:
                     line = line.strip()
                     if not line:  # skip empty lines

tasks/spellingbee.py

@@ -119,7 +119,7 @@ class SpellingBee(Task):
         self.split = split
         filename = WORD_LIST_URL.split("/")[-1]
         word_list_path = download_file_with_lock(WORD_LIST_URL, filename)
-        with open(word_list_path) as f:
+        with open(word_list_path, 'r', encoding='utf-8') as f:
             words = [line.strip() for line in f]
         self.words = words
 
@@ -238,7 +238,7 @@ class SimpleSpelling(Task):
         self.split = split
         filename = WORD_LIST_URL.split("/")[-1]
         word_list_path = download_file_with_lock(WORD_LIST_URL, filename)
-        with open(word_list_path) as f:
+        with open(word_list_path, 'r', encoding='utf-8') as f:
             words = [line.strip() for line in f]
         rng = random.Random(42)
         rng.shuffle(words) # use a different word order than the SpellingBee task