chore: bump emulated Node version to 26.5.1
The node_compat suite was bumped to Node 26.5.1 in #36391, but
`deno_node::NODE_VERSION` still reported 26.3.0. The compat report reads
its `nodeVersion` field from the vendored suite, so published reports
claimed a version the runtime did not emulate.
These are bumped in two different places, so also assert in the report
that the suite's version matches what the runtime reports through
`process.versions.node`, to stop the two drifting again silently.
