Add django-constance to requirements

Note that I had to edit the requirements manually since I can't
run pip-compile right now: no MariaDb.

requirements/requirements.in

@@ -51,3 +51,7 @@ certifi>=2023.7.22
 pyjwt>=2.4.0
 urllib3>=1.26.18
 sqlparse>=0.4.4
+
+# Dynamic settings
+django-constance
+django-picklefield  # Required by django-constance for database backend

requirements/requirements.txt

@@ -51,13 +51,16 @@ django==4.2.11
     #   django-extensions
     #   django-filter
     #   django-model-utils
+    #   django-picklefield
     #   django-tables2
 django-allauth==0.54.0
     # via -r requirements/requirements.in
 django-anvil-consortium-manager @ git+https://github.com/UW-GAC/[email protected]
     # via -r requirements/requirements.in
 django-autocomplete-light==3.11.0
     # via django-anvil-consortium-manager
+django-constance==3.1.0
+    # via -r requirements/requirements.in
 django-crispy-forms==2.1
     # via
     #   -r requirements/requirements.in
@@ -79,6 +82,10 @@ django-maintenance-mode==0.21.1
     # via -r requirements/requirements.in
 django-model-utils==4.4.0
     # via -r requirements/requirements.in
+django-picklefield==3.1
+    # via
+    #   -r requirements/requirements.in
+    #   django-constance
 django-simple-history==3.5.0
     # via
     #   -r requirements/requirements.in