Optimize bashunit

[antonio-gg-dev]

📚 Description

By removing the call to the deprecated setUp/tearDown functions and modifying the implementation of the execute_function_if_exists and unset_if_exists helpers, I've managed to reduce the execution time of the library's own tests by around 15% in my local environment.

To calculate these times, I have been running the following script while making changes and taking an average of the times:

for i in {1..10}; do make test | grep "Time taken: " >> result_2_f; done

After all the changes, the results I have obtained from main vs this branch are as follows:

Removing the deprecations meant a reduction of about 5%, and modifying the implementation of the helpers accounted for the remaining 10% reduction.

🔖 Changes

• Remove support to deprecated setUp/tearDown functions
• Optimize test execution speed

✅ To-do list

• I updated the CHANGELOG.md to reflect the new feature or fix
• I updated the documentation to reflect the changes

[Chemaclass]

I love it! Kudos!