[BUG] wrktool in Circuit Breaker doesn't work successfully

**Describe the bug**
A clear and concise description of what the bug is.

**Platform**
ECS

**To Reproduce**
Steps to reproduce the behavior:
1. move to `aws-app-mesh-examples/walkthroughs/howto-circuit-breakers`
2. read [README](https://github.com/aws/aws-app-mesh-examples/blob/main/walkthroughs/howto-circuit-breakers/README.md) and run commands
3. the command `./infrastructure/ecs-service` is failed
4. check the service's log on ECS

ECS task's error log:

```
OCI runtime create failed: runc create failed: unable to start container process: exec: "python3": stat python3: no such file or directory
```

**Expected behavior**
A container runs successfully from wrktool container image.

**Config files, and API responses**
This dockerfile is used for building wrktool container image.

https://github.com/aws/aws-app-mesh-examples/blob/5d9a248129e7da3b9cd37e868e491c134df87d20/walkthroughs/howto-circuit-breakers/src/wrktool/Dockerfile

**Additional context**
The line as below might be root cause of this error. Python3 has dependency for Python3 pip, so that Python3 package is uninstalled by this command.

```
yum -y remove python3-pip git-core && \
```

When I commented out this code, the error doesn't occur.

Start with walkthroughs/howto-circuit-breakers/src/wrktool/Dockerfile, especially the yum command that removes python3-pip and git-core. Rebuild the wrktool image, rerun ./infrastructure/ecs-service from walkthroughs/howto-circuit-breakers, and check the ECS task log. Done means the container starts successfully without the python3 executable error.

Written by the indexing model from the issue text.