fix: c2pa v0.75.4 (#217)

* fix: Update expected SDK version in unit tests

* fix: Update c2pa version to v0.75.3

* fix: Update SDK version in unit tests to 0.75.4

* fix: Update c2pa version to v0.75.4

* fix: Update comment to clarify legacy settings loading

Author: tmathern

c2pa-native-version.txt

@@ -1 +1 @@
-c2pa-v0.75.2
+c2pa-v0.75.4

tests/test_unit_tests.py

@@ -43,7 +43,7 @@
 
 def load_test_settings_json():
     """
-    Load default trust configuration test settings from a
+    Load default (legacy) trust configuration test settings from a
     JSON config file and return its content as JSON-compatible dict.
     The return value is used to load settings.
 
@@ -67,7 +67,7 @@ def load_test_settings_json():
 
 class TestC2paSdk(unittest.TestCase):
     def test_sdk_version(self):
-        self.assertIn("0.75.2", sdk_version())
+        self.assertIn("0.75.4", sdk_version())
 
 
 class TestReader(unittest.TestCase):