build: Fix the way the ODD warning works

[paulgessinger]

@asalzburger (and the CI) were experiencing false-positive warnings about the ODD files missing. This PR should fix that.

[codecov]

Codecov Report

Merging #960 (21425a7) into main (8f241f5) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #960   +/-   ##
=======================================
  Coverage   48.46%   48.46%           
=======================================
  Files         334      334           
  Lines       17067    17067           
  Branches     8074     8074           
=======================================
  Hits         8271     8271           
  Misses       3094     3094           
  Partials     5702     5702           

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