build(deps): bump slackapi/slack-github-action from 1.27 to 2.0

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.27 to 2.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v1.27...v2.0)

---
updated-dependencies:
- dependency-name: slackapi/slack-github-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/manual_new_rdp.yml

@@ -68,7 +68,7 @@ jobs:
 
       - name: Notification Slack
         id: slack
-        uses: slackapi/slack-github-action@v1.27
+        uses: slackapi/slack-github-action@v2.0
         if: "${{ github.event.inputs.notify-slack == 'true' }}"
         with:
           payload: '{"blocks":[{"type":"section","text":{"type":"mrkdwn","text":":newspaper: La GeoRDP du ${{ env.DATE_FR_LONG }} a été créée et attend vos contributions :writing_hand: !"}},{"type":"section","fields":[{"type":"mrkdwn","text":"Créée par *${{ github.actor }}* via GitHub Action."}]},{"type":"actions","elements":[{"type":"button","text":{"type":"plain_text","emoji":true,"text":":squid: Voir la PR (GitHub)"},"url":"${{ steps.cpr.outputs.pr_url }}"},{"type":"button","text":{"type":"plain_text","emoji":true,"text":":eye: Voir la preview (Netlify)"},"style":"primary","url":"https://preview-pullrequest-${{steps.cpr.outputs.pr_number}}--geotribu-preprod.netlify.app/"}]}]}'