fix: Correct FastAPI version constraint in toml

The upper bound for the `fastapi` dependency is adjusted from `<1.119.0` to `<0.119.0`.

Close #3422

Co-authored-by: George Weale <gweale@google.com>
PiperOrigin-RevId: 830465681

Author: GWeale

pyproject.toml

@@ -30,7 +30,7 @@ dependencies = [
   "anyio>=4.9.0, <5.0.0;python_version>='3.10'",             # For MCP Session Manager
   "authlib>=1.5.1, <2.0.0",                                  # For RestAPI Tool
   "click>=8.1.8, <9.0.0",                                    # For CLI tools
-  "fastapi>=0.115.0, <1.119.0",                              # FastAPI framework
+  "fastapi>=0.115.0, <0.119.0",                              # FastAPI framework
   "google-api-python-client>=2.157.0, <3.0.0",               # Google API client discovery
   "google-cloud-aiplatform[agent_engines]>=1.125.0, <2.0.0", # For VertexAI integrations, e.g. example store.
   "google-cloud-bigquery-storage>=2.0.0",