Fix the trigger-translations job in the post-release workflow (#5217)

Author: jbordonado

.github/workflows/post-release-updates.yml

@@ -100,6 +100,11 @@ jobs:
     needs: get-last-released-version
     runs-on: ubuntu-20.04
     steps:
+      - name: "Checkout repository (trunk)"
+        uses: actions/checkout@v3
+        with:
+          ref: 'trunk'
+          
       - name: "Trigger translations update on GlotPress"
         uses: ./.github/actions/trigger-translations
         with:

changelog/fix-5216-translations-job-for-post-release

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Fix translations job from the post-release workflow