feat: add nv25-skeleton

[rjan90]

ref: #2075

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.73%. Comparing base (9172edc) to head (a3f209b).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2076   +/-   ##
=======================================
  Coverage   75.72%   75.73%           
=======================================
  Files         154      154           
  Lines       15686    15691    +5     
=======================================
+ Hits        11878    11883    +5     
  Misses       3808     3808           

Files with missing lines	Coverage Δ
fvm/src/gas/price_list.rs	77.62% <ø> (ø)
fvm/src/machine/default.rs	73.26% <100.00%> (+1.39%)	⬆️
shared/src/version/mod.rs	0.00% <ø> (ø)