Added Disjoint Set Algorithm with Merge Accounts program in Graph section

[karthik124a]

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase.
• All functions and variable names follow Java naming conventions.
• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• All new code is formatted with clang-format -i --style=file path/to/your/file.java

[codecov-commenter]

Codecov Report

❌ Patch coverage is 89.58333% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.86%. Comparing base (b312567) to head (f201546).

Files with missing lines	Patch %	Lines
...main/java/com/thealgorithms/graph/DisjointSet.java	89.58%	2 Missing and 3 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #6837      +/-   ##
============================================
+ Coverage     77.84%   77.86%   +0.01%     
- Complexity     6394     6406      +12     
============================================
  Files           733      734       +1     
  Lines         21333    21381      +48     
  Branches       4183     4193      +10     
============================================
+ Hits          16607    16648      +41     
- Misses         4058     4061       +3     
- Partials        668      672       +4     

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

🚀 New features to boost your workflow:

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

[github-actions]

This pull request has been automatically closed because its workflows or checks failed and it has been inactive for more than 14 days. Please fix the workflows and reopen if you'd like to continue. Merging from main/master alone does not count as activity.