ci: fix workflows running twice (#3)

Why
- when people with write access write a branch to this repo, then use it in a PR, it causes the PR to run the workflow "test" twice

What
- fix this bug. "test" will now only run one time

Author: NovemLinguae

.github/workflows/test.yml

@@ -1,6 +1,10 @@
 name: test
 
-on: [push, pull_request]
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
 
 jobs:
   test: