remove dupe of get_letter_timings

it was moved from admin to utils a while ago

app/utils.py

@@ -2,7 +2,6 @@ import csv
 import os
 import re
 import unicodedata
-from collections import namedtuple
 from datetime import datetime, timedelta, timezone
 from functools import wraps
 from io import StringIO
@@ -356,37 +355,6 @@ def email_or_sms_not_enabled(template_type, permissions):
     return (template_type in ['email', 'sms']) and (template_type not in permissions)
 
 
-def get_letter_timings(upload_time):
-
-    LetterTimings = namedtuple(
-        'LetterTimings',
-        'printed_by, is_printed, earliest_delivery, latest_delivery'
-    )
-
-    # shift anything after 5pm to the next day
-    processing_day = gmt_timezones(upload_time) + timedelta(hours=(7))
-
-    print_day, earliest_delivery, latest_delivery = (
-        processing_day + timedelta(days=days)
-        for days in {
-            'Wednesday': (1, 3, 5),
-            'Thursday': (1, 4, 5),
-            'Friday': (3, 5, 6),
-            'Saturday': (2, 4, 5),
-        }.get(processing_day.strftime('%A'), (1, 3, 4))
-    )
-
-    printed_by = print_day.astimezone(pytz.timezone('Europe/London')).replace(hour=15, minute=0)
-    now = datetime.utcnow().replace(tzinfo=pytz.timezone('Europe/London'))
-
-    return LetterTimings(
-        printed_by=printed_by,
-        is_printed=(now > printed_by),
-        earliest_delivery=earliest_delivery,
-        latest_delivery=latest_delivery,
-    )
-
-
 def gmt_timezones(date):
     date = dateutil.parser.parse(date)
     forced_utc = date.replace(tzinfo=pytz.utc)