idtools: return errors for >u32 specification

[cyphar]

This isn't a huge issue, but it could cause user confusion if they
provide too large a value.

Signed-off-by: Aleksa Sarai [email protected]

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.70%. Comparing base (71d012d) to head (e597e6a).
Report is 3 commits behind head on main.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #558      +/-   ##
==========================================
+ Coverage   73.68%   73.70%   +0.01%     
==========================================
  Files          60       60              
  Lines        4903     4906       +3     
==========================================
+ Hits         3613     3616       +3     
  Misses        941      941              
  Partials      349      349              

Files with missing lines	Coverage Δ
pkg/idtools/idtools.go	100.00% <100.00%> (ø)