Reformat everything with black.

I had to undo the u string prefix removals to not drop Python 2 compatibility.
That's why black isn't enabled in antsibull-nox.toml yet.

plugins/module_utils/serial.py

@@ -21,12 +21,12 @@ def th(number):
     mod_100 = abs_number % 100
     if mod_100 not in (11, 12, 13):
         if mod_10 == 1:
-            return 'st'
+            return "st"
         if mod_10 == 2:
-            return 'nd'
+            return "nd"
         if mod_10 == 3:
-            return 'rd'
-    return 'th'
+            return "rd"
+    return "th"
 
 
 def parse_serial(value):
@@ -35,14 +35,17 @@ def parse_serial(value):
     """
     value = to_native(value)
     result = 0
-    for i, part in enumerate(value.split(':')):
+    for i, part in enumerate(value.split(":")):
         try:
             part_value = int(part, 16)
             if part_value < 0 or part_value > 255:
-                raise ValueError('the value is not in range [0, 255]')
+                raise ValueError("the value is not in range [0, 255]")
         except ValueError as exc:
-            raise ValueError("The {idx}{th} part {part!r} is not a hexadecimal number in range [0, 255]: {exc}".format(
-                idx=i + 1, th=th(i + 1), part=part, exc=exc))
+            raise ValueError(
+                "The {idx}{th} part {part!r} is not a hexadecimal number in range [0, 255]: {exc}".format(
+                    idx=i + 1, th=th(i + 1), part=part, exc=exc
+                )
+            )
         result = (result << 8) | part_value
     return result
 
@@ -53,5 +56,5 @@ def to_serial(value):
     """
     value = convert_int_to_hex(value).upper()
     if len(value) % 2 != 0:
-        value = '0' + value
-    return ':'.join(value[i:i + 2] for i in range(0, len(value), 2))
+        value = "0" + value
+    return ":".join(value[i : i + 2] for i in range(0, len(value), 2))