corrected changelog for 3.25 release

[nr-swilloughby]

Updates CHANGELOG to reflect a minor fix to the securityagent code that had previously been merged to develop but wasn't included in the changelog for this release.

[nr-swilloughby]

This also adds a missing bit of information about the previous release in the section for that release.

[codecov-commenter]

Codecov Report

Merging #783 (ba9626f) into develop (09b6fac) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #783   +/-   ##
========================================
  Coverage    91.93%   91.93%           
========================================
  Files           41       41           
  Lines         2171     2171           
========================================
  Hits          1996     1996           
  Misses         136      136           
  Partials        39       39           

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