fix(ci/test): run tests on all PRs

since the test check is required to merge to main
by GitHub's branch protection, we need the check to
run on all PRs regardless of contents

no need to run on push to main since PRs are required

.github/workflows/dotnet-test.yml

@@ -1,21 +1,8 @@
 name: Run tests
 
 on:
-  push:
-    branches: [ main ]
-    paths:
-      - .github/workflows/dotnet-test.yml
-      - 'src/**'
-      - 'tests/**'
-      - HashFields.sln
-
   pull_request:
     branches: [ "*" ]
-    paths:
-      - .github/workflows/dotnet-test.yml
-      - 'src/**'
-      - 'tests/**'
-      - HashFields.sln
 
 jobs:
   test: