fix: register missing LTX nodes as supporting BYOK (#423)

Part of #409. Addressing failure in test_griptape_proxy_node_byok.py,
specifically `test_every_proxy_node_exposes_shared_byok_ui`.

LTXVideoExtend (PR #183) and LTXVideoToVideoHDR (PR #188) were added
as GriptapeProxyNode subclasses but never registered in either BYOK
config map. Add them with the LTX provider config, matching the pattern
of other LTX nodes.

Author: feltech

griptape_nodes_library/proxy/proxy_api_key_providers.py

@@ -127,7 +127,9 @@ class ProxyApiKeyProviderConfig:
     "LTXAudioToVideoGeneration": LTX,
     "LTXImageToVideoGeneration": LTX,
     "LTXTextToVideoGeneration": LTX,
+    "LTXVideoExtend": LTX,
     "LTXVideoRetake": LTX,
+    "LTXVideoToVideoHDR": LTX,
     "MinimaxHailuoVideoGeneration": MINIMAX,
     "OmnihumanSubjectDetection": SEED,
     "OmnihumanSubjectRecognition": SEED,