build(github): use pull_request_target

Using `pull_request` event won't work with forks due to security concerns. `pull_request_target` is what we should be using.

Signed-off-by: Ahmed T. Ali <[email protected]>

.github/workflows/dependent-issues.yml

@@ -2,7 +2,16 @@ name: Dependent Issues
 
 on:
   issues:
-  pull_request:
+    types:
+      - opened
+      - edited
+      - reopened
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - reopened
+      - synchronize
   schedule:
     - cron: '0 0 * * *' # schedule daily check
 
@@ -24,4 +33,4 @@ jobs:
 
           # (Optional) A comma-separated list of keywords. Default
           # "depends on, blocked by"
-          keywords: depends on, blocked by
+          keywords: depends on, blocked by