Add ubuntu 26.04 to integration test matrix (#733)

Co-authored-by: Kidus Asrade <kidusasr@amazon.com>

Author: kidmun

generator/resources/ec2_linux_test_matrix.json

@@ -32,6 +32,17 @@
     "binaryName": "amazon-cloudwatch-agent.deb",
     "family": "linux"
   },
+  {
+    "os": "ubuntu-26",
+    "username": "ubuntu",
+    "instanceType":"t3a.medium",
+    "installAgentCommand": "go run ./install/install_agent.go deb",
+    "ami": "cloudwatch-agent-integration-test-ubuntu-26*",
+    "caCertPath": "/etc/ssl/certs/ca-certificates.crt",
+    "arc": "amd64",
+    "binaryName": "amazon-cloudwatch-agent.deb",
+    "family": "linux"
+  },
   {
     "os": "ubuntu-22.04",
     "username": "ubuntu",