fix: 'Bill Type: Invalid Choice: could not coerce' error

Error introduced in #1290. Fixes #1293. WTForms needs to be bumped to >=2.3.2
as it includes a fix to `SelectField` which is required for this change to work.

See:
  - https://wtforms.readthedocs.io/en/3.1.x/changes/#version-2-3-2
  - https://github.com/wtforms/wtforms/pull/598

ihatemoney/models.py

@@ -58,7 +58,7 @@ class BillType(Enum):
 
     @classmethod
     def choices(cls):
-        return [(choice, choice.value) for choice in cls]
+        return [(choice.value, choice.value) for choice in cls]
 
 
 db = SQLAlchemy()

pyproject.toml

@@ -39,7 +39,7 @@ dependencies = [
     "Flask-SQLAlchemy>=2.4,<3",
     "Flask-Talisman>=0.8,<2",
     "Flask-WTF>=0.14.3,<2",
-    "WTForms>=2.3.1,<3.2",
+    "WTForms>=2.3.3,<3.2",
     "Flask>=2,<3",
     "Werkzeug>=2,<3",
     "itsdangerous>=2,<3",