[Draft] Remove deprecated publish_rate from diff_drive_controller

[Bhavin-umatiya]

Description

Following the deprecation in PR #2245, this follow-up PR removes the deprecated publish_rate parameter and its associated logic from diff_drive_controller.

This includes:

1. Removal of publish_rate from diff_drive_controller_parameter.yaml.
2. Removal of publish_rate_, publish_period_, and previous_publish_timestamp_ from the controller header.
3. Removal of publication throttling logic from the control loop; it now publishes at every cycle.

This PR is set as a Draft as requested by @christophfroehlich, to be merged after the next project sync.

[mergify]

This pull request is in conflict. Could you fix it @Bhavin-umatiya?

[christophfroehlich]

Thank you. Please rebase this on top of master as the deprecation PR got merged now.

[Bhavin-umatiya]

Thank you, @christophfroehlich. I have rebased the branch on the latest master and resolved the merge conflicts. The PR is now up to date with the merged deprecation code.

[codecov]

Codecov Report

❌ Patch coverage is 95.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 84.69%. Comparing base (fc570f8) to head (1bbdc98).

Files with missing lines	Patch %	Lines
...iff_drive_controller/src/diff_drive_controller.cpp	95.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2259      +/-   ##
==========================================
+ Coverage   84.68%   84.69%   +0.01%     
==========================================
  Files         153      153              
  Lines       15319    15307      -12     
  Branches     1332     1329       -3     
==========================================
- Hits        12973    12965       -8     
+ Misses       1858     1856       -2     
+ Partials      488      486       -2     

Flag	Coverage Δ
unittests	84.69% <95.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...iff_drive_controller/src/diff_drive_controller.cpp	80.93% <95.00%> (+0.51%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.