Update workflow to use new ESM and NPM workspace structure

[heitorlessa]

As of now, the monthly roadmap workflow uses the previous GH Script based solution:

actions/.github/workflows/monthly_roadmap_reminder.yml

Line 37 in bb0f1c8

const { default: main } = await import('${{ github.workspace }}/packages/reporting/src/index.mjs')

This issue tracks work to migrate to ESM and use this instead:

Need to follow Andrea's guidance on how to best install and call our code from Actions.

const github = new GitHub({token: PASS_TOKEN })
const report = MonthlyRoadmapReport({ github })

await report.create()