Docs: updated PR template with proper make command for running unit tests

[ezawadski]

AI Description

This PR makes changes to the pull request template for the Cohere Toolkit.

• The PR title has been updated to include a more specific area of modification, such as "interface", "frontend", "model", "tools", or "backend".
• The PR message has been modified to instruct contributors to delete the entire checklist and replace it with a new one.
• The checklist now includes a section for "Dependencies", where contributors can list any dependencies required for the change.
• The "Lint and test" section has been updated to run make run-unit-tests instead of make run-tests.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.84%. Comparing base (cf12000) to head (f980342).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #898   +/-   ##
=======================================
  Coverage   77.84%   77.84%           
=======================================
  Files         259      259           
  Lines       11177    11177           
=======================================
  Hits         8701     8701           
  Misses       2476     2476           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.