set timeout error as training error

[maikia]

Previously I set the timeout error to checking_error. This should not be the case. Conda workers considers timeout as training error and AWS worker does not have the timeout error implemented at all. (hence #497)

Weirdly tests which should have been failing on Ci passed on previous PR (#495) and failed only for the release PR (https://github.com/paris-saclay-cds/ramp-board/tree/0.7.X).

Once this is corrected, and if green another bug release will be made

[codecov]

Codecov Report

Merging #498 (bce2704) into master (e9a3c1d) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #498      +/-   ##
==========================================
- Coverage   93.65%   93.64%   -0.02%     
==========================================
  Files          99       99              
  Lines        8633     8633              
==========================================
- Hits         8085     8084       -1     
- Misses        548      549       +1     

Impacted Files	Coverage Δ
ramp-engine/ramp_engine/dispatcher.py	97.61% <100.00%> (ø)
ramp-engine/ramp_engine/base.py	92.68% <0.00%> (-1.22%)	⬇️

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