GitHub Action using npx fails with message /usr/bin/env: 'node': No such file or directory - node.js

Question

I'm creating a nodejs GitHub Action that relies on npx to run semantic-release:
src/index.ts (extract, bundled to dist/index.js)
import * as core from '#actions/core'
import * as exec from '#actions/exec'
import * as github from '#actions/github'
;(async () => {
const githubRegistry: string = `https://npm.pkg.github.com/${github.context.repo.owner}`
const githubToken: string = core.getInput('github_token', { required: true })
await exec.exec('npx', ['semantic-release'], {
NPM_CONFIG_REGISTRY: githubRegistry,
NPM_TOKEN: githubToken,
GITHUB_TOKEN: githubToken
})
})()
action.yml (extract)
inputs:
github_token:
required: true
runs:
using: node12
main: dist/index.js
.github/workflows/release.yml
on:
push:
branches:
- main
jobs:
release:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout#v2
- uses: actions/setup-node#v1
with:
node-version: 12
- run: yarn
- uses: ./
with:
github_token: ${{ secrets.GITHUB_TOKEN }}
When the release workflow is ran on GitHub, it fails with the following output:
/opt/hostedtoolcache/node/12.19.0/x64/bin/npx semantic-release
/usr/bin/env: 'node': No such file or directory
Error: The process '/opt/hostedtoolcache/node/12.19.0/x64/bin/npx' failed with exit code 127
It looks like npx is trying to run node but could not find it.
I would appreciate any help, thanks :)