feat: added setup maven step to the backend pipeline

.gitea/workflows/backend-ci.yml

@@ -25,14 +25,11 @@ jobs:
         java-version: '21'
         distribution: 'temurin'
         cache: 'maven'
-<<<<<<< HEAD
 
     - name: Set up Maven
       uses: stCarolas/setup-maven@v5
       with:
         maven-version: '3.6.3'
-=======
->>>>>>> c5433df (feat: removed backend pipeline step for caching m2)
         
     - name: Run Maven tests
       working-directory: ./backend