Increase email size limit to 2MBby pulling in new utils

This is because GOV.UK has hit the email size limit with their
weekly digest email.

requirements.txt

@@ -31,7 +31,7 @@ notifications-python-client==5.7.0
 # PaaS
 awscli-cwlogs==1.4.6
 
-git+https://github.com/alphagov/notifications-utils.git@43.5.6#egg=notifications-utils==43.5.6
+git+https://github.com/alphagov/notifications-utils.git@43.5.7#egg=notifications-utils==43.5.7
 
 # gds-metrics requires prometheseus 0.2.0, override that requirement as 0.7.1 brings significant performance gains
 prometheus-client==0.8.0
@@ -42,14 +42,14 @@ alembic==1.4.3
 amqp==1.4.9
 anyjson==0.3.3
 attrs==20.3.0
-awscli==1.18.194
+awscli==1.18.197
 bcrypt==3.2.0
 billiard==3.3.0.23
 bleach==3.2.1
 blinker==1.4
 boto==2.49.0
-boto3==1.16.34
-botocore==1.19.34
+boto3==1.16.37
+botocore==1.19.37
 certifi==2020.12.5
 chardet==3.0.4
 click==7.1.2
@@ -62,7 +62,6 @@ geojson==2.5.0
 govuk-bank-holidays==0.8
 greenlet==0.4.17
 idna==2.10
-importlib-metadata==3.1.1
 Jinja2==2.11.2
 jmespath==0.10.0
 kombu==3.0.37
@@ -71,8 +70,8 @@ MarkupSafe==1.1.1
 mistune==0.8.4
 monotonic==1.5
 orderedset==2.0.3
-packaging==20.7
-phonenumbers==8.12.14
+packaging==20.8
+phonenumbers==8.12.15
 pyasn1==0.4.8
 pycparser==2.20
 pyparsing==2.4.7
@@ -93,4 +92,3 @@ statsd==3.3.0
 urllib3==1.26.2
 webencodings==0.5.1
 Werkzeug==1.0.1
-zipp==3.4.0