removed obsolete code

requirements.txt

@@ -14,4 +14,3 @@ pytest~=7.0.1
 funcy==1.17
 fpdf==1.7.2
 PyMuPDF==1.19.6
-frozendict==2.3.2

test/integration_tests/serve_test.py

@@ -5,7 +5,6 @@ from itertools import starmap, repeat, chain
 from operator import itemgetter
 
 import pytest
-from frozendict import frozendict
 from funcy import compose, lzip, lpluck
 
 from pyinfra.default_objects import (
@@ -24,10 +23,6 @@ from test.utils.input import pair_data_with_queue_message
 logger = logging.getLogger(__name__)
 
 
-def freeze(data, metadata):
-    return data, frozendict(metadata)
-
-
 @pytest.fixture
 def test_components(url, queue_manager, storage):
 
@@ -148,7 +143,7 @@ def test_serving(
         metadata = repeat({})
         targets = lzip(target_data_items, metadata)
 
-    targets = sorted(starmap(freeze, targets), key=itemgetter(0))
+    targets = sorted(targets, key=itemgetter(0))
 
     data_message_pairs = pair_data_with_queue_message(data_metadata_packs)