fix: adding throttled status code for server unavailable error in salesforce

[shrouti1507]

What are the changes introduced in this PR?

For salesforce when the salesforce server is busy or unavailable we were throwing retriable which was being failed eventually by retrying 3 times.
Now, we are throwing 429 status code appropriately.

What is the related Linear task?

Resolves INT-2847

Please explain the objectives of your changes below

Put down any required details on the broader aspect of your changes. If there are any dependent changes, mandatorily mention them here

Any changes to existing capabilities/behaviour, mention the reason & what are the changes ?

N/A

Any new dependencies introduced with this change?

N/A

Any new generic utility introduced or modified. Please explain the changes.

N/A

Any technical or performance related pointers to consider with the change?

N/A

@coderabbitai review

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Developer checklist

• My code follows the style guidelines of this project

• No breaking changes are being introduced.

• All related docs linked with the PR?

• All changes manually tested?

• Any documentation changes needed with this change?

• Is the PR limited to 10 file changes?

• Is the PR limited to one linear task?

• Are relevant unit and component test-cases added in new readability format?

Reviewer checklist

• Is the type of change in the PR title appropriate as per the changes?

• Verified that there are no credentials or confidential data exposed with the changes.

[devops-github-rudderstack]

Test report for this run is available at: https://test-integrations-dev.s3.amazonaws.com/integrations-test-reports/rudder-transformer/3862/test-report.html

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.02%. Comparing base (bbd31a1) to head (69b5669).
Report is 10 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3862      +/-   ##
===========================================
- Coverage    89.02%   89.02%   -0.01%     
===========================================
  Files          610      610              
  Lines        32918    32957      +39     
  Branches      7779     7789      +10     
===========================================
+ Hits         29305    29339      +34     
+ Misses        3330     3305      -25     
- Partials       283      313      +30     

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[sonarcloud]

Quality Gate passed

Issues
19 New issues
1 Accepted issue

Measures
0 Security Hotspots
92.9% Coverage on New Code
0.3% Duplication on New Code

See analysis details on SonarCloud