ci: fix issue with ubi image name replacing plus with a dash

[TomerFi]

The issue with the latest CI failures starting this one originates in #85, the addition of the UBI variant of the image. The cause is the docker build command replaces the + with - and not the expected _. A similiar issue was resolved in stacklok/toolhive#2363.

@dmartinol @blkt ^^

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.72%. Comparing base (cc21648) to head (cd944a5).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #103   +/-   ##
=======================================
  Coverage   65.72%   65.72%           
=======================================
  Files          45       45           
  Lines        2611     2611           
=======================================
  Hits         1716     1716           
  Misses        772      772           
  Partials      123      123           

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[dmartinol]

Great memory, thank you!