remove security email from domainInfo, create migration, simplify form_valid set security email

src/registrar/migrations/0020_remove_domaininformation_security_email.py

@@ -0,0 +1,16 @@
+# Generated by Django 4.2 on 2023-05-17 17:05
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("registrar", "0019_alter_domainapplication_organization_type"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="domaininformation",
+            name="security_email",
+        ),
+    ]

src/registrar/models/domain_information.py

@@ -200,12 +200,6 @@ class DomainInformation(TimeStampedModel):
         blank=True,
         help_text="Acknowledged .gov acceptable use policy",
     )
-    security_email = models.EmailField(
-        max_length=320,
-        null=True,
-        blank=True,
-        help_text="Security email for public use",
-    )
 
     def __str__(self):
         try:

src/registrar/views/domain.py

@@ -90,7 +90,7 @@ class DomainNameserversView(DomainPermission, FormMixin, DetailView):
         domain.set_nameservers(nameservers)
 
         messages.success(
-            self.request, "The name servers for this domain have been updated"
+            self.request, "The name servers for this domain have been updated."
         )
         # superclass has the redirect
         return super().form_valid(formset)
@@ -129,17 +129,13 @@ class DomainSecurityEmailView(DomainPermission, FormMixin, DetailView):
     def form_valid(self, form):
         """The form is valid, call setter in model."""
 
-        # Set the security email from the from
+        # Set the security email from the form
-        try:
+        new_email = form.cleaned_data["security_email"]
-            new_email = form.cleaned_data["security_email"]
-        except KeyError:
-            # no server information in this field, skip it
-            pass
         domain = self.get_object()
         domain.set_security_email(new_email)
 
         messages.success(
-            self.request, "The security email for this domain have been updated"
+            self.request, "The security email for this domain have been updated."
         )
         # superclass has the redirect
         return redirect(self.get_success_url())