fix: check that cfn template exists

[nikhname]

Issue #, if available:

Description of changes:

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[codecov]

Codecov Report

Merging #6163 (ba27629) into master (24b5523) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #6163   +/-   ##
=======================================
  Coverage   57.06%   57.06%           
=======================================
  Files         467      467           
  Lines       21486    21486           
  Branches     4056     4056           
=======================================
  Hits        12261    12261           
  Misses       8270     8270           
  Partials      955      955           

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[github-actions]

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