Fix typos found in tests/unittests

[luzpaz]

Description

Found via codespell -q 3 -S thirdparty -L ane,ans,childs,globaly,inout,ist,oce,ontop,parm,parms,te. Fixed manually.

How Has This Been Tested?

n/a

Screenshots, that help to understand the changes(if applicable):

n/a

Checklist:

• A test for the new functionality was added.
• All tests run without failure.
• The new code complies with the TiGL style guide.
• New classes have been added to the Python interface.
• API changes were documented properly in tigl.h.

[joergbrech]

And thanks again for the spell check :)

[codecov-commenter]

Codecov Report

Merging #923 (745b6f0) into master (0648987) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #923   +/-   ##
=======================================
  Coverage   69.52%   69.52%           
=======================================
  Files         298      298           
  Lines       24974    24974           
=======================================
  Hits        17363    17363           
  Misses       7611     7611