chore: restrict marshmallow to <v4 (#580)

* chore: restrict marshmallow to <v4

because a lots of stuff goes wrong in v4: see #575 
probably we should get rid of it together with attrs and just use pydantic where we'd have none of the problems (e.g. also not #218 and our dependency on fuhrysteve/marshmallow-jsonschema#169 which we really should remove in the long term.

* reset requirements for doc creation

---------

Co-authored-by: DeltaDaniel <[email protected]>

Author: hf-kklein

dev_requirements/requirements-docs.txt

@@ -55,7 +55,7 @@ packaging==24.1
     #   sphinx
 pygments==2.18.0
     # via sphinx
-pytz==2025.1
+pytz==2025.2
     # via
     #   ahbicht (pyproject.toml)
     #   efoli

pyproject.toml

@@ -26,7 +26,7 @@ dependencies = [
     "attrs>=21.4.0",
     "lark>=1.1.4",
     "inject",
-    "marshmallow",
+    "marshmallow<4",
     "marshmallow_enum",
     "maus>=0.6.0",
     "pytz",