Backport Node.js 22.22.3 and pnpm support to 5-65-stable

What does this MR do?

Backports the following master changes to 5-65-stable (the builder line used by GitLab 19.3, tag 5.65.0):

• !496 (merged) – Bump Node Version to 22.22.3 (pnpm requires Node.js >= 22.13)
• !498 (merged) – Add pnpm support (new pnpm snippet, PNPM_VERSION=11.11.0 in docker/VERSIONS, default snippets list, and AmazonLinux 2 x86_64/arm64 Dockerfiles)

Why is this needed?

Prometheus 3.13.2 requires pnpm and a newer Node.js toolchain to build its web UI assets. GitLab 19-3-stable builds with the 5.65.x builder line, so these runtime dependency updates must be backported here rather than moving 19.3 to a newer builder (5.66.0 would pull in unrelated builder changes). Once merged and tagged (e.g. 5.65.1), the new builder image can be referenced by the omnibus-gitlab backport MR omnibus-gitlab!9745 (merged).

Related links

• omnibus-gitlab 19-3-stable Prometheus backport: omnibus-gitlab!9745 (merged)
• Original master MRs: !496 (merged), !498 (merged)
• omnibus-gitlab#10031 (closed)