Run tests on all PRs (#526)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index ce72243..f20131c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -2,8 +2,6 @@
 
 on:
   pull_request:
-    branches:
-      - main
   push:
     branches:
       - main