chore: Add new dependency for the Agent Identity feature

PiperOrigin-RevId: 930299067

Author: google-genai-bot

pyproject.toml

@@ -65,6 +65,7 @@ optional-dependencies.a2a = [
   "a2a-sdk>=0.3.4,<0.4",
 ]
 optional-dependencies.agent-identity = [
+  "google-cloud-agentidentitycredentials>=0.1,<0.2",
   "google-cloud-iamconnectorcredentials>=0.1,<0.2",
 ]
 optional-dependencies.all = [
@@ -195,6 +196,7 @@ optional-dependencies.test = [
   "e2b>=2,<3",
   "gepa>=0.1",
   "google-api-python-client>=2.157,<3",
+  "google-cloud-agentidentitycredentials>=0.1,<0.2",
   "google-cloud-aiplatform[agent-engines,evaluation]>=1.148.1,<2",
   "google-cloud-bigquery>=2.2",
   "google-cloud-bigquery-storage>=2",