Building from specific branch and building after merging to master

Currently I have a master branch and a development branch. I want the build process to be triggered only if anything is merged to dev branch and I have already added "only" reference. Once all the work is done on dev branch I merged the dev branch to master which did not trigger any build. Is there a way to trigger build both ways,

  1. when any feature branch is merged to dev branch
  2. When that dev branch is merged to master (since master is what goes into PROD)

Below is my sample gitlab CI file:

image: docker:latest

stages:
  - cloning
  - build
  - deploy

cloning: 
  stage: cloning
  only:
    - DEV
  
  script:
    - echo "Starting to clone the repo...."
    - echo $PATH
    - pwd
    - ls -l
    - echo "Moving to next stage"
    
    
build:
  stage: build
  only:
    - DEV
  
  script: 
    - echo "Starting the build Process..."
    - pwd
    - echo "Build process completed.."
    
deploy:
  stage: deploy
  when: manual
  only:
    - master
  
  script:
    - echo "Deploy to DEV.."
    - pwd
    - echo "Deployment complete.."

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