Revert "ci: give holesky-test workflow access to secrets via pull_req…

…uest_target (#153)"

This reverts commit 15b10fd.
The commit was doing things very wrong. I hadn't understood how pull_request_target works.
Was causing the workflow to run against main branch head commit instead of PR commit.
We will need to find another solution to the problem of letting external contributors run this workflow.

.github/workflows/holesky-test.yml

@@ -3,11 +3,7 @@ name: holesky-test
 on:
   push:
     branches: [ "main" ]
-  # pull_request_target is needed so that external contributors that create PRs from a forked repo
-  # have access to the secrets needed to run the tests. There are security implications to this,
-  # see https://stackoverflow.com/questions/74957218/what-is-the-difference-between-pull-request-and-pull-request-target-event-in-git
-  # MAKE SURE TO ONLY ALLOW RUNNING THIS WORKFLOW AFTER REVIEWING THE PR!
-  pull_request_target:
+  pull_request:
     branches: [ "main" ]
 
 jobs: