FR-5759 - Use meta/gadget.yaml for the gadget yaml path for classic

[upils]

No description provided.

[codecov]

Codecov Report

Merging #159 (b110b11) into main (1865cb8) will decrease coverage by 0.11%.
The diff coverage is 100.00%.

❗ Current head b110b11 differs from pull request most recent head 1828810. Consider uploading reports for the commit 1828810 to get more accurate results

@@            Coverage Diff             @@
##             main     #159      +/-   ##
==========================================
- Coverage   90.62%   90.52%   -0.11%     
==========================================
  Files          13       13              
  Lines        2634     2606      -28     
==========================================
- Hits         2387     2359      -28     
  Misses        215      215              
  Partials       32       32              

Files	Coverage Δ
internal/statemachine/classic_states.go	96.41% <100.00%> (-0.09%)	⬇️
internal/statemachine/common_states.go	99.10% <100.00%> (+<0.01%)	⬆️
internal/statemachine/pack_states.go	100.00% <100.00%> (ø)
internal/statemachine/snap_states.go	100.00% <100.00%> (ø)
internal/statemachine/state_machine.go	98.02% <ø> (ø)

... and 2 files with indirect coverage changes

[sil2100]

This looks good and as expected, but we also talked about improving the error wording in case meta/gadget.yaml is missing after the gadget is built. I can't seem to find anything related to that here - is the error wording explanatory enough? Like, if someone builds an image with a gadget tree that doesn't install to meta/, will they instantly know that the solution is to copy the file over to the directory? Since just an error of 'file missing' might make them a bit confused, as we have no explicit guidelines about what to install where.

[sil2100]

LGTM!