Allow latest OS in devcontainers (rapidsai#1169)

This PR removes the OS suffix from devcontainers, allowing the upstream devcontainer images to determine the OS version.

Contributes to rapidsai/build-planning#200.

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - Kyle Edwards (https://github.com/KyleFromNVIDIA)

URL: rapidsai#1169

Author: bdice

.devcontainer/cuda12.9-conda/devcontainer.json

@@ -5,7 +5,7 @@
     "args": {
       "CUDA": "12.9",
       "PYTHON_PACKAGE_MANAGER": "conda",
-      "BASE": "rapidsai/devcontainers:25.10-cpp-mambaforge-ubuntu22.04"
+      "BASE": "rapidsai/devcontainers:25.10-cpp-mambaforge"
     }
   },
   "runArgs": [

.devcontainer/cuda12.9-pip/devcontainer.json

@@ -5,7 +5,7 @@
     "args": {
       "CUDA": "12.9",
       "PYTHON_PACKAGE_MANAGER": "pip",
-      "BASE": "rapidsai/devcontainers:25.10-cpp-cuda12.9-ucx1.18.0-openmpi-ubuntu22.04"
+      "BASE": "rapidsai/devcontainers:25.10-cpp-cuda12.9-ucx1.18.0-openmpi5.0.7"
     }
   },
   "runArgs": [