task/import: Make probe non-strict for recordings import

[victorges]

We've been getting errors turning recordings with no audio into assets. This shouldn't
be really a problem for recordings since all we do is download the muxed mp4s and save
them on the object store. They can have no audio without problems (we only needed to
require audio for the oold joy4 workflow).

[codecov]

Codecov Report

Merging #155 (cc21120) into main (fa0bad9) will decrease coverage by 0.00519%.
The diff coverage is 0.00000%.

@@                 Coverage Diff                 @@
##                main        #155         +/-   ##
===================================================
- Coverage   11.01695%   11.01176%   -0.00519%     
===================================================
  Files             14          14                 
  Lines           2124        2125          +1     
===================================================
  Hits             234         234                 
- Misses          1873        1874          +1     
  Partials          17          17                 

Impacted Files	Coverage Δ
task/import.go	0.00000% <0.00000%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fa0bad9...cc21120. Read the comment docs.

Impacted Files	Coverage Δ
task/import.go	0.00000% <0.00000%> (ø)