fixed_issue_ updating_experiment_tags_or_description

[khushi1310]

Fixes #5251

Proposed changes

Fixed an issue where updating experiment tags or description was triggering a duplicate name validation error.
In the UpdateChaosExperiment function, the duplicate name validation was being called unconditionally without checking if the experiment name had actually changed. This meant:

• When you edit an existing experiment (e.g., adding tags/description)
• The system checks if an experiment with that name already exists
• It finds the current experiment itself as a "duplicate"
• Returns the error: "experiment name should be unique, duplicate experiment found with name: khushitest2"

Types of changes

What types of changes does your code introduce to Litmus? Put an x in the boxes that apply

• New feature (non-breaking change which adds functionality)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices applies)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING doc
• I have signed the commit for DCO to be passed.
• Lint and unit tests pass locally with my changes
• [] I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have added necessary documentation (if appropriate)

Dependency

• No dependencies required

Special notes for your reviewer:

Steps to Test:

1. Create a new experiment with name "test1"
2. Edit the experiment and add new tags
3. Save changes - should work without duplicate name error
4. Verify tags are saved correctly in db