Update title to issue in slack notifications

[arku]

Description

Title -> Issue

Checklist

• linter status: 100% pass
• changes don't break existing behavior
• commit message follows commit guidelines

/cc @PixelantDesign

[codecov]

Codecov Report

Merging #2153 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2153   +/-   ##
=======================================
  Coverage   27.82%   27.82%           
=======================================
  Files         136      136           
  Lines       11169    11169           
  Branches     1509     1509           
=======================================
  Hits         3108     3108           
  Misses       7951     7951           
  Partials      110      110

Impacted Files	Coverage Δ
app/dashboard/notifications.py	16.76% <ø> (ø)	⬆️

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