ci: run release on Node, not Deno (fix release regression)

[KyleJune]

Summary

Fixes the release regression introduced by #95. The Release job failed on the
main push (run):

Command: .../v2.6.7/linux/deno publish --no-check --allow-dirty --dry-run
error: unrecognized subcommand   tip: a similar subcommand exists: 'publish'
(DEP0190) DeprecationWarning: Passing args to a child process with shell option true ...

Root cause: @sebbo2002/semantic-release-jsr downloads its own Deno binary
and shell: true-spawns deno publish. Under Deno's Node child_process
emulation that spawn mangles the args (the subcommand token gets concatenated),
so deno reports a valid subcommand as "unrecognized". #95 had moved
semantic-release from npx (real Node) onto deno run; this plugin is built for
a Node host and only works there. The Deno-native move was right for
semantic-release core but wrong for this one plugin.

Changes

• Run semantic-release on Node again — restore actions/setup-node + npx.
• Keep the supply-chain hardening by pinning every npx --package to an
  exact version (jsr plugin stays 3.2.1; npm:semantic-release@25.0.5 etc.).
  npx has no lockfile, so the exact version is the pin.
• Remove the semantic-release imports ci: harden release pipeline against supply-chain #95 added to deno.json (npx fetches
  the tooling) — minimumDependencyAge, the SHA-pinned actions, cache: false
  on the publish job, and the contents: read token from ci: harden release pipeline against supply-chain #95 all stay.

Testing

Locally on this branch with the exact pinned npx … semantic-release --dry-run
under Node v24.14: all six plugins load with no version/engine conflict. This
restores the exact npx-under-Node configuration that published every release
through 0.8.0; #95's only release-execution change (npx→deno run) is what
broke it, and that's what's reverted.

Follow-up

For full transitive integrity on the npx path, a committed package-lock.json +
npm ci would pin beyond the direct packages. Left as a follow-up to keep this
fix minimal.