feat(workflows): Ensure that PR titles conform to the conventional commits spec

[Styrke]

Note that we probably want to default to PR titles for squash merge commit messages on repositories that use this.

[aimeerivers]

please add a workflow_call:trigger to enable it to be called from other workflows.

then you can test it with something like this:

name: Check commit title

on:
    issues:
        types:
            - opened
            - reopened
    pull_request:
        types:
            - opened
            - reopened

jobs:
    lint-pr:
        uses: hedia-team/.github/.github/workflows/lint-pr.yml@conventional-commits-pr
        secrets: inherit