Deprecate ko deps

[imjasonh]

Fixes #769

[imjasonh]

It seems that Deprecated in cobra means the command also gets hidden from ko help and generated Markdown docs. If that's not something we want, I can try to figure out how to make that not happen.

[codecov-commenter]

Codecov Report

Merging #770 (8c207b4) into main (7ac1a03) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #770      +/-   ##
==========================================
+ Coverage   51.27%   51.30%   +0.02%     
==========================================
  Files          44       44              
  Lines        3321     3323       +2     
==========================================
+ Hits         1703     1705       +2     
  Misses       1401     1401              
  Partials      217      217              

Impacted Files	Coverage Δ
pkg/commands/deps.go	14.42% <100.00%> (+0.83%)	⬆️
pkg/commands/run.go	22.12% <100.00%> (+0.69%)	⬆️