ci: Add Gitleaks pre-commit hook for detecting potential credentials

[wajidzahoor-dls]

Instructions to reviewer on how to test:

1. Pull this branch and verify that pre-commit hooks are active.
   Run the following command to confirm gitleaks is correctly set up:

   pre-commit run --all-files
   

   This should include output from gitleaks, detecting potential hardcoded secrets.

   Note: It is assumed that the CI environment handles installing gitleaks as part of the pre-commit configuration.
   For local testing, the following setup was used:

   python3 -m venv .venv
   source .venv/bin/activate
   pip install pre-commit
   pre-commit install --hook-type pre-commit
   pre-commit run --all-files
   

2. Test gitleaks manually by attempting to commit a file containing a fake secret (e.g., a fake API key or private key).
   The commit should be blocked by gitleaks if the secret is detected. Note that detection may include false positives or occasionally miss some secrets (false negatives).

   For more information, including configuration options for customizing detection rules, refer to the official documentation:
   https://github.com/gitleaks/gitleaks

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.49%. Comparing base (41c09c6) to head (b688f47).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1153   +/-   ##
=======================================
  Coverage   94.49%   94.49%           
=======================================
  Files          41       41           
  Lines        2544     2544           
=======================================
  Hits         2404     2404           
  Misses        140      140           

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