Rework CI to trigger executions within each module (#148)

.github/workflows/spring-batch-bigquery.yml

@@ -1,23 +1,24 @@
 name: Spring Batch BigQuery
 
 on:
-  push:
-    branches: [ main ]
   pull_request:
-    branches: [ main ]
+    paths:
+      - 'spring-batch-bigquery/**'
+  push:
+    paths:
+      - 'spring-batch-bigquery/**'
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout source code
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
       - name: Set up JDK 17
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: 17
+          java-version: '17'
           cache: 'maven'
       - name: Build with Maven
-        run: mvn -B package --file pom.xml
-        working-directory: spring-batch-bigquery
+        run: mvn -B package
+        working-directory: spring-batch-bigquery