Fixes:
```
Error: Create EC2 instances failed: 'ec2.ServiceResource' object has no attribute 'describe_images'
Traceback (most recent call last):
File "/osbuild-composer/tools/build-rpms.py", line 218, in <module>
stage_generate_rpms(cleanup_actions, args)
File "/osbuild-composer/tools/build-rpms.py", line 175, in stage_generate_rpms
create_ec2_instances, cleanup_actions, args, keyname)
File "/osbuild-composer/tools/build-rpms.py", line 66, in stage
ret = fun(*args)
File "/osbuild-composer/tools/build-rpms.py", line 109, in create_ec2_instances
img = ec2.describe_images(ImageIds=[arch_info[a]["ImageId"]])
AttributeError: 'ec2.ServiceResource' object has no attribute 'describe_images'
```
make ansible playbooks arch-agnostic
extract embedded bash script into separate file with parameters
update packer template to support aarch64
Convert parts of bash script to python code that can start multi-arch instances to build RPMS
