Executer les actions de déploiement depuis master

Pour des raisons de sécurité, éviter d'avoir une fuite de secret via un
attaquant qui modifirait l'action et qui ferait fuiter un secret.

.github/workflows/deploy.yaml

@@ -1,7 +1,5 @@
 name: Déploiement
 on:
-  pull_request:
-    types: [opened, synchronize]
   push:
     branches: [master, demo, next]
   pull_request_target: 
@@ -93,7 +91,7 @@ jobs:
           enable-commit-comment: false
           github-deployment-environment: ${{ needs.deploy-context.outputs.env-name }}
           alias: ${{ needs.deploy-context.outputs.env-name }}${{ matrix.site && format('-{0}', matrix.site) }}
-          deploy-message: ${{ github.event.pull_request.title || needs.deploy-context.outputs.env-name }} (${{ matrix.site || 'fr' }})
+          deploy-message: ${{ github.event.pull_request_target.title || needs.deploy-context.outputs.env-name }} (${{ matrix.site || 'fr' }})
 
           # Disabled because we create our own customized comment
           enable-pull-request-comment: false
@@ -129,21 +127,21 @@ jobs:
 
   post-comment:
     runs-on: ubuntu-18.04
-    if: github.event_name == 'pull_request'
+    if: github.event_name == 'pull_request_target'
     needs: [deploy-preview, deploy-context]
     steps:
       - name: Find Comment
         uses: peter-evans/find-comment@v1
         id: find-comment
         with:
-          issue-number: ${{ github.event.pull_request.number }} #e.g. 1
+          issue-number: ${{ github.event.pull_request_target.number }} #e.g. 1
           comment-author: 'github-actions[bot]'
           body-includes: netlify
       - name: Create comment
         uses: peter-evans/create-or-update-comment@v1
         with:
           comment-id: ${{ steps.find-comment.outputs.comment-id }}
-          issue-number: ${{ github.event.pull_request.number }}
+          issue-number: ${{ github.event.pull_request_target.number }}
           edit-mode: replace
           body: |
             🚀 La branche est déployée ! 
@@ -229,7 +227,7 @@ jobs:
           parallel: true
           group: ${{ matrix.site }}-${{ matrix.browser }}-viewport_${{ matrix.viewport }}
         env:
-          COMMIT_INFO_MESSAGE: ${{ github.event.pull_request.title }}
+          COMMIT_INFO_MESSAGE: ${{ github.event.pull_request_target.title }}
 
   e2e-test-production:
     env:
@@ -308,4 +306,4 @@ jobs:
           parallel: true
           group: ${{ matrix.site }}-${{ matrix.browser }}-viewport_${{ matrix.viewport }}
         env:
-          COMMIT_INFO_MESSAGE: ${{ github.event.pull_request.title }}
+          COMMIT_INFO_MESSAGE: ${{ github.event.pull_request_target.title }}