feat: Upgrade Python dependency edx-enterprise

feat: Makes ``career_engagement_network_message`` field nullable in ``EnterpriseCustomer``.

Commit generated by workflow `openedx/edx-platform/.github/workflows/upgrade-one-python-dependency.yml@refs/heads/master`

requirements/constraints.txt

@@ -23,7 +23,7 @@ click>=8.0,<9.0
 # The team that owns this package will manually bump this package rather than having it pulled in automatically.
 # This is to allow them to better control its deployment and to do it in a process that works better
 # for them.
-edx-enterprise==4.20.2
+edx-enterprise==4.20.3
 
 # Stay on LTS version, remove once this is added to common constraint
 Django<5.0

requirements/edx/base.txt

@@ -453,7 +453,7 @@ edx-drf-extensions==10.3.0
     #   edx-when
     #   edxval
     #   openedx-learning
-edx-enterprise==4.20.2
+edx-enterprise==4.20.3
     # via
     #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/kernel.in

requirements/edx/development.txt

@@ -729,7 +729,7 @@ edx-drf-extensions==10.3.0
     #   edx-when
     #   edxval
     #   openedx-learning
-edx-enterprise==4.20.2
+edx-enterprise==4.20.3
     # via
     #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/doc.txt

requirements/edx/doc.txt

@@ -526,7 +526,7 @@ edx-drf-extensions==10.3.0
     #   edx-when
     #   edxval
     #   openedx-learning
-edx-enterprise==4.20.2
+edx-enterprise==4.20.3
     # via
     #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/base.txt

requirements/edx/testing.txt

@@ -559,7 +559,7 @@ edx-drf-extensions==10.3.0
     #   edx-when
     #   edxval
     #   openedx-learning
-edx-enterprise==4.20.2
+edx-enterprise==4.20.3
     # via
     #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/base.txt