github: only run unit tests in CI

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

.github/workflows/pull_request.yml

@@ -3,12 +3,8 @@ on: [pull_request]
 name: Check pull request
 jobs:
   test-pr:
-    runs-on: macos-latest
-    strategy:
-      matrix:
-        api-level: [23, 29]
+    runs-on: ubuntu-latest
     steps:
-
     - name: Check if relevant files have changed
       uses: actions/github-script@0.9.0
       id: service-changed
@@ -34,15 +30,9 @@ jobs:
       run: mkdir -p ~/.gradle ; cp .github/ci-gradle.properties ~/.gradle/gradle.properties
 
     - uses: burrunan/gradle-cache-action@v1
-      name: Restore cache
-
-    - name: Run instrumentation tests
-      if: ${{ steps.service-changed.outputs.result == 'true' }}
-      uses: reactivecircus/android-emulator-runner@v2.11.0
+      name: Run unit tests
       with:
-        api-level: ${{ matrix.api-level }}
-        target: default
-        script: ./gradlew :app:connectedDebugAndroidTest
+        arguments: testDebug
 
     - name: (Fail-only) upload test report
       if: failure()