Calling BCO uses global python

Using the Readme instructions to add to path causes the tool to call the globally set python version, which can lead to execution errors..

```shell
File "/usr/local/bin/bco", line 965, in create_mapping_file
index_path = line.removeprefix("On instance").removesuffix(":\n")
AttributeError: 'str' object has no attribute 'removeprefix'
```
Identified by this post:
https://stackoverflow.com/questions/67730095/removeprefix-for-string-object-is-not-an-attribute