Detect container runtime beyond Docker in telemetry (#10132)

* telemetry: detect container runtime, not just Docker

`is_docker` only checks `/.dockerenv`, a marker the Docker daemon creates.
containerd/CRI-O (Kubernetes), Podman, etc. don't, so a containerized node —
notably every Qdrant Cloud pod — reported `is_docker: false`, indistinguishable
from bare metal.

Add a `container_runtime` field (enum: none/docker/kubernetes/other) detected
from well-known markers, most specific first: KUBERNETES_SERVICE_HOST →
/.dockerenv → other container markers → none. Only docker and kubernetes are
enumerated (the modes that matter for Qdrant); the rest fold into `other`.
`is_docker` is kept but derived (== docker). Detected once via LazyLock.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Regenerate OpenAPI spec

Add the ContainerRuntime schema and container_runtime field.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/redoc/master/openapi.json

@@ -11933,6 +11933,7 @@
       "RunningEnvironmentTelemetry": {
         "type": "object",
         "required": [
+          "container_runtime",
           "cpu_flags",
           "is_docker"
         ],
@@ -11948,6 +11949,9 @@
           "is_docker": {
             "type": "boolean"
           },
+          "container_runtime": {
+            "$ref": "#/components/schemas/ContainerRuntime"
+          },
           "cores": {
             "type": "integer",
             "format": "uint",
@@ -11996,6 +12000,16 @@
           }
         }
       },
+      "ContainerRuntime": {
+        "description": "Container runtime Qdrant is running under (`none` if bare metal).",
+        "type": "string",
+        "enum": [
+          "none",
+          "docker",
+          "kubernetes",
+          "other"
+        ]
+      },
       "CpuEndian": {
         "type": "string",
         "enum": [