Allow Django 5.0, remove support for older versions, bump to 0.4

pyproject.toml

 [tool.poetry]
 name = "django-iconify"
-version = "0.3"
+version = "0.4"
 description = "Iconify API implementation and tools for Django projects"
 authors = ["Dominik George <dominik.george@teckids.org>"]
 license = "Apache-2.0"
@@ -19,8 +19,8 @@ packages = [
 include = ["LICENSE", "examples/"]
 
 [tool.poetry.dependencies]
-python = "^3.7"
-Django = ">2.1,<5.0"
+python = "^3.10"
+Django = ">4.2,<6.0"
 
 [tool.poetry.dev-dependencies]