ci: stop building Node.js 20 binaries

[arv]

The v1.1.7 release workflow failed in the prebuild jobs, so nothing was published (the publish job was skipped). The cause is StatementIterator::NextBatch (#57), which uses v8::LocalVector. That API only exists from NODE_MODULE_VERSION 127 (Node 22) on, and NODE_BUILD_CMD_LEGACY also built binaries for Node 20.

Node 20 is past end of life and isn't in engines (22.x || 24.x), and mono-internal only needs Node 22+. So this drops -t 20.0.0 from the prebuilds instead of guarding the code; an earlier commit here added a guard, which is now reverted. The Node 20 container images stay, because they only host the build tool.

Local results:

• Node 22, 24 and 26: build, and 366 tests pass.
• Node 23: builds, and 365 tests pass (one is pending).

PR CI only tests Node 22, 24 and 26, which is why #57's CI didn't catch the Node 20 failure.

[Copilot]

🟢 Approval recommended

The compatibility change is scoped and has no unresolved review issues.

No open issues 🎉

What changed in this PR

Updates nextBatch() to compile on Node versions without v8::LocalVector.

Changes:

• Uses LocalVector for Node module versions 127+.
• Uses std::vector as a fallback for older versions.

File	Description
src/​objects/​statement-iterator.cpp	Adds the Node-version-compatible value container fallback.

_{Review effort: Lite}