ci: add path filters, concurrency, and gradle/actions/setup-gradle

Author: GeiserX

.github/workflows/ci.yml

@@ -3,8 +3,25 @@ on:
   workflow_dispatch:
   push:
     branches: [main]
+    paths:
+      - 'app/**'
+      - 'gradle/**'
+      - '*.gradle*'
+      - 'gradle.properties'
+      - '.github/workflows/ci.yml'
   pull_request:
     branches: [main]
+    paths:
+      - 'app/**'
+      - 'gradle/**'
+      - '*.gradle*'
+      - 'gradle.properties'
+      - '.github/workflows/ci.yml'
+
+concurrency:
+  group: ci-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -14,7 +31,7 @@ jobs:
         with:
           distribution: temurin
           java-version: 17
-      - run: chmod +x gradlew
+      - uses: gradle/actions/setup-gradle@v4
       - run: ./gradlew jacocoTestReport
       - uses: codecov/codecov-action@v5
         if: github.event_name == 'push'