Changed latest event sender query from keyword field to text field

[bshien]

Description

Fixing a bug in the Maintainer Dashboard where events are not found when the username in MAINTAINER.md and GitHub differ in case.

Issues Resolved

Part of #57

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.87%. Comparing base (dbc4a1b) to head (8c0a548).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #106   +/-   ##
=========================================
  Coverage     86.87%   86.87%           
  Complexity      318      318           
=========================================
  Files            69       69           
  Lines          1767     1767           
  Branches         81       80    -1     
=========================================
  Hits           1535     1535           
  Misses          195      195           
  Partials         37       37           

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