fix(gpu): use the ubuntu24.04 CUDA base so bundled uWS can load

The CUDA runtime base was ubuntu22.04 (glibc 2.35). This image bundles
uWebSockets.js, copied from the build stage, and its prebuilt Linux binaries
link against GLIBC_2.38 — so the addon could not load on that base. It is the
same failure documented at the top of ./Dockerfile, which is why the standard
image runs on Debian trixie rather than bookworm (glibc 2.36).

Switches the default to nvidia/cuda:13.3.0-cudnn-runtime-ubuntu24.04
(glibc 2.39) and updates the CUDA 12.x override example to the matching
ubuntu24.04 tag. All four tag combinations were confirmed present on Docker Hub.

Documents the glibc floor next to the ARG: the point of this ARG is that
operators override it for older driver branches, and an override back to an
ubuntu22.04 base would silently break uWS again.

Latent until now — the build has failed outright since #496, so this base was
never actually produced.

Credit: flagged by gemini-code-assist on #628.

Author: kriszyp

Dockerfile-gpu

@@ -5,12 +5,18 @@ ARG NODE_VERSION=24
 # architecture in the 13.x line (Maxwell/Pascal/Volta were dropped). The 13.x
 # runtime requires an R580+ host driver; on hosts pinned to an older driver
 # branch, override with a CUDA 12.x cudnn-runtime base, e.g.:
-#   --build-arg CUDA_RUNTIME_IMAGE=nvidia/cuda:12.6.3-cudnn-runtime-ubuntu22.04
+#   --build-arg CUDA_RUNTIME_IMAGE=nvidia/cuda:12.6.3-cudnn-runtime-ubuntu24.04
+#
+# Keep the ubuntu24.04 variant (glibc 2.39) whichever CUDA line you pick. This
+# image bundles uWebSockets.js (copied from the build stage below), whose
+# prebuilt Linux binaries link against GLIBC_2.38 — ubuntu22.04 ships glibc 2.35
+# and the addon fails to load there, the same failure that put the standard
+# image on Debian trixie. See the note at the top of ./Dockerfile.
 #
 # Must stay above the first FROM: an ARG referenced by a FROM has to be declared
 # in the global scope, before any stage. Declared after a FROM it belongs to that
 # stage, and the later FROM expands it to an empty base name.
-ARG CUDA_RUNTIME_IMAGE=nvidia/cuda:13.3.0-cudnn-runtime-ubuntu22.04
+ARG CUDA_RUNTIME_IMAGE=nvidia/cuda:13.3.0-cudnn-runtime-ubuntu24.04
 
 FROM docker.io/node:${NODE_BUILD_VERSION} AS build