fix: ci workflow triggert

In order to execute the action on fork, we had to change the pull_request trigger to pull_request_target

Author: leonsteinhaeuser

.github/workflows/pr_size.yml

@@ -1,6 +1,8 @@
 name: Pull Request automations
 
-on: pull_request
+on:
+  pull_request_target:
+  pull_request:
 
 jobs:
   size-label:

.github/workflows/project_automations.yml

@@ -4,6 +4,9 @@ on:
   issues:
     types:
       - opened
+  pull_request_target:
+    types:
+      - opened
   pull_request:
     types:
       - opened