fix(scripts/image): Creating a new docker version with git tool

[Orenef11]

I've created and pushed the new image https://hub.docker.com/layers/scylladb/scylla-cassandra-unit-tests/python3.8-20220117/images/sha256-435ca242eaa59948864eda9fa118fe4819c1c838517743a6c8896572c6e8d4f8?context=explore

docker run -it scylladb/scylla-cassandra-unit-tests:python3.8-20220117 bash                                                                                              
root@7a2e47a2c5b0:/# git -v
unknown option: -v
usage: git [--version] [--help] [-C <path>] [-c <name>=<value>]
           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]
           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
           <command> [<args>]
root@7a2e47a2c5b0:/# git --version
git version 2.20.1
root@7a2e47a2c5b0:/# mvn -v
Apache Maven 3.6.0
Maven home: /usr/share/maven
Java version: 11.0.13, vendor: Debian, runtime: /usr/lib/jvm/java-11-openjdk-amd64
Default locale: en, platform encoding: UTF-8
OS name: "linux", version: "5.13.0-25-generic", arch: "amd64", family: "UNIX"

[fruch]

@Orenef11 where is the change to the dockerfile ?