Recently , I had faced this issue in deploying my application in tomcat webserver .
This error is due to incorrect installation of GIT in your local drive . You can either clone your Repository in such a way that ,
post build actions -> execute shell -> git clone "your repo link"

Still if it doesn't workout , you can go for these steps :

Jenkins URL fix issue :

1️⃣ Go to Jenkins Dashboard → Your Job → Configure
2️⃣ Under "Build" Section → Click "Add Build Step" → Select "Execute Shell"
3️⃣ Enter the following commands:

cd /var/lib/jenkins/workspace/job/github-repolink

git pull origin master # Optional: Pull latest changes if git clone doesn't work

mvn clean package

ls -lh target/ # Verify if .war file is created

4️⃣ Save the job and run the build.

Check this out .