fix: add tests for deleting recurring events

[meetulr]

What kind of change does this PR introduce?

Adds comprehensive tests and corrects the code for removeEvent mutation.

Issue Number:

Fixes #2053 #2054

Did you add tests for your changes?

Yes

[github-actions]

Our Pull Request Approval Process

We have these basic policies to make the approval process smoother for our volunteer team.

Testing Your Code

Please make sure your code passes all tests. Our test code coverage system will fail if these conditions occur:

1. The overall code coverage drops below the target threshold of the repository
2. Any file in the pull request has code coverage levels below the repository threshold
3. Merge conflicts

The process helps maintain the overall reliability of the code base and is a prerequisite for getting your PR approved. Assigned reviewers regularly review the PR queue and tend to focus on PRs that are passing.

Reviewers

Do not assign reviewers. Our Queue Monitors will review your PR and assign them.
When your PR has been assigned reviewers contact them to get your code reviewed and approved via:

1. comments in this PR or
2. our slack channel

Reviewing Your Code

Your reviewer(s) will have the following roles:

1. arbitrators of future discussions with other contributors about the validity of your changes
2. point of contact for evaluating the validity of your work
3. person who verifies matching issues by others that should be closed.
4. person who gives general guidance in fixing your tests

CONTRIBUTING.md

Read our CONTRIBUTING.md file. Most importantly:

1. PRs with issues not assigned to you will be closed by the reviewer
2. Fix the first comment in the PR so that each issue listed automatically closes

Other

1. 🎯 Please be considerate of our volunteers' time. Contacting the person who assigned the reviewers is not advised unless they ask for your input. Do not @ the person who did the assignment otherwise.
2. Read the CONTRIBUTING.md file make

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.66%. Comparing base (c40215c) to head (00d00f3).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2158      +/-   ##
===========================================
+ Coverage    96.72%   97.66%   +0.93%     
===========================================
  Files          340      340              
  Lines        22943    22915      -28     
  Branches      1990     2038      +48     
===========================================
+ Hits         22192    22379     +187     
+ Misses         746      531     -215     
  Partials         5        5              

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