docs(agent): add notice file and remove extra license file

Author: ayuskauskas

agent/skyhook-agent/LICENSE.txt

@@ -0,0 +1,8 @@
+Skyhook Open Source Software
+Copyright (c) 2024, NVIDIA CORPORATION.
+
+This product includes software developed at
+NVIDIA CORPORATION (https://www.nvidia.com/).
+
+This software make use of code with licenses:
+ * jsonschema: MIT https://github.com/python-jsonschema/jsonschema/blob/main/COPYING