Restore C2PA certificate validation and refresh compatible dependencies

.github/dependabot.yml

@@ -18,11 +18,18 @@ updates:
     # extra) requires NumPy <2.4, mirrored by `constraint-dependencies` in
     # pyproject.toml, and this project keeps tokenizers below 0.23 for the stable
     # Transformers path. Keep Dependabot on the compatible lines until those
-    # constraints move.
+    # constraints move. Transformers 5.16+ requires tokenizers 0.23.1+,
+    # and Diffusers requires huggingface-hub <2. Mirror the manifest bounds.
     ignore:
       - dependency-name: "numpy"
         versions:
           - ">=2.4"
+      - dependency-name: "transformers"
+        versions:
+          - ">=5.16"
+      - dependency-name: "huggingface-hub"
+        versions:
+          - ">=2"
       - dependency-name: "tokenizers"
         versions:
           - ">=0.23"