gitlab-ci, how to prevent another trigger when pushing from a runner - gitlab-ci

Question

Here is how the pipeline works
when a push on master (work as expected): build project && push jar to dev
when a tag is created (woesn't work as expected):
build project
increment pom.xml version and push pom.xml to
push jar to server
But when I do step 2, it retrigger another build in the CI.
How can I push and avoid triggering the job in this case ?
Here is the full gitlab-ci.yml:
image: maven:3.6.0-jdk-10
variables:
APP_NAME: demo
MAVEN_OPTS: -Dmaven.repo.local=/cache/maven.repository
stages:
- build
- deploy_dev
- deploy_prod
build:
stage: build
script:
- mvn package -P build
- mv target/*.jar target/$APP_NAME.jar
artifacts:
untracked: true
deploy_dev:
before_script:
- 'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'
- eval $(ssh-agent -s)
- ssh-add <(echo "$SSH_PRIVATE_KEY")
- '[[ -f /.dockerenv ]] && mkdir -p ~/.ssh && echo "$KNOWN_HOST" > ~/.ssh/known_hosts'
- mkdir -p ~/.ssh
- '[[ -f /.dockerenv ]] && echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config'
stage: deploy_dev
environment:
name: dev
url: http://devsb01:9999
dependencies:
- build
only:
- master
except:
- tags
script:
- ssh root#devsb01 "service $APP_NAME stop"
- scp target/$APP_NAME.jar root#devsb01:/var/apps/$APP_NAME/
- ssh root#devsb01 "service $APP_NAME start"
deploy_prod:
before_script:
- 'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'
- eval $(ssh-agent -s)
- ssh-add <(echo "$SSH_PRIVATE_KEY")
- '[[ -f /.dockerenv ]] && mkdir -p ~/.ssh && echo "$KNOWN_HOST" > ~/.ssh/known_hosts'
- mkdir -p ~/.ssh
- '[[ -f /.dockerenv ]] && echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config'
stage: deploy_prod
environment:
name: production
dependencies:
- build
only:
- tags
except:
- branches
script:
- mvn versions:set -DnewVersion=$CI_COMMIT_REF_NAME
- git config --global user.name "gitlab-ci"
- git config --global user.email "gitlab-ci#unc.nc"
- git --version
- git status
- git add pom.xml
- git commit -m "increment pom version"
- git push http://gitlab-ci:${GITLABCI_PWD}#gitlab.unc.nc/dsi-infogestion/demo.git HEAD:master
- git status
- ssh root#prodsb01 "service $APP_NAME stop"
- scp target/$APP_NAME.jar root#prodsb01:/var/apps/$APP_NAME/
- ssh root#prodsb01 "service $APP_NAME start"

Answer 1

I had the string '[ci skip]' in the commit message and it works:
git commit -m "increment pom version [ci skip]"