typo fix in utilities.jl

[arhik]

typo : mech should be mechanism in contact_location function.

[codecov]

Codecov Report

Merging #91 (2be2ea2) into main (ac93056) will decrease coverage by 0.04%.
The diff coverage is 0.00%.

❗ Current head 2be2ea2 differs from pull request most recent head 4ce72be. Consider uploading reports for the commit 4ce72be to get more accurate results

@@            Coverage Diff             @@
##             main      #91      +/-   ##
==========================================
- Coverage   87.51%   87.47%   -0.04%     
==========================================
  Files          89       89              
  Lines        5086     5086              
==========================================
- Hits         4451     4449       -2     
- Misses        635      637       +2     

Files Changed	Coverage Δ
src/contacts/utilities.jl	28.57% <0.00%> (ø)

... and 1 file with indirect coverage changes