Bump -utils to get latest version of Shapely

This was pinned in [^1] but I'm not sure why - we ought to pin it
in -utils if it needs pinning. Version 1.7.1 doesn't work with Mac
M1 installs of Homebrew - unless you manually hack the library.

As per [^2], we don't think the calculation change matters much.

[^1]: 969e7a6dbd (diff-eee0e41c3756911002e040cf5a8f66b004bb66c8ff1a359bb8ba35d86081e80cR21)
[^2]: 8a10d74fc5

requirements.in

@@ -21,7 +21,6 @@ pytz==2021.3
 # Should be pinned until a new gunicorn release greater than 20.1.0 comes out. (Due to eventlet v0.33 compatibility issues)
 git+https://github.com/benoitc/gunicorn.git@1299ea9e967a61ae2edebe191082fd169b864c64#egg=gunicorn[eventlet]==20.1.0
 notifications-python-client==6.3.0
-Shapely==1.7.1
 rtreelib==0.2.0
 fido2==0.9.3
 importlib-metadata==4.2.0
@@ -30,7 +29,7 @@ pyproj==3.2.1
 # PaaS
 awscli-cwlogs>=1.4,<1.5
 itsdangerous==1.1.0  # pyup: <2
-notifications-utils @ git+https://github.com/alphagov/notifications-utils.git@55.1.0
+notifications-utils @ git+https://github.com/alphagov/notifications-utils.git@55.1.1
 govuk-frontend-jinja @ git+https://github.com/alphagov/govuk-frontend-jinja.git@v0.5.8-alpha
 
 # gds-metrics requires prometheseus 0.2.0, override that requirement as later versions bring significant performance gains

requirements.txt

@@ -196,10 +196,8 @@ s3transfer==0.4.2
     # via
     #   awscli
     #   boto3
-shapely==1.7.1
-    # via
-    #   -r requirements.in
-    #   notifications-utils
+shapely==1.8.1.post1
+    # via notifications-utils
 six==1.16.0
     # via
     #   awscli-cwlogs

tests/app/main/views/test_broadcast.py

@@ -934,8 +934,8 @@ def test_preview_broadcast_areas_page(
             [[7, 8], [9, 10], [11, 12]],
         ],
         [
-            'An area of 1,000 square miles Will get the alert',
-            'An extra area of 1,000 square miles is Likely to get the alert',
+            'An area of 800 square miles Will get the alert',
+            'An extra area of 2,000 square miles is Likely to get the alert',
             'Unknown number of phones',
         ]
     ),