feat: simplify unicodes_per_glyphset code (#4)

Author: bdraco

src/esphome_glyphsets/__init__.py

@@ -22,9 +22,9 @@ def unicodes_per_glyphset(glyphset_name: str) -> list[int]:
     nam_path = GLYPHSETS_NAM_PATH / f"{glyphset_name}.nam"
     if not nam_path.exists():
         return []
-    character_set: set[int] = set()
-    for line in nam_path.read_text().splitlines():
-        unicode = line.partition(" ")[0]
-        if unicode.startswith("0x"):
-            character_set.add(int(unicode[2:], 16))
+    character_set = {
+        int(line.partition(" ")[0][2:], 16)
+        for line in nam_path.read_text().splitlines()
+        if line.startswith("0x")
+    }
     return sorted(character_set)