Fix log level on killed tasks

[vtleonardo]

Scope

When a task is being killed (e.g snapshots) its context (created by the scheduler) is canceled which bubbles up an error. This is normal behavior and should be filtered to not show to the user the message as a level Error. The error level should be only used when I task exits with an error without being killed.

[codecov-commenter]

Codecov Report

Merging #63 (e18541c) into main (dff6b0e) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main      #63      +/-   ##
==========================================
- Coverage   45.65%   45.63%   -0.03%     
==========================================
  Files         214      214              
  Lines       38484    38499      +15     
==========================================
- Hits        17569    17568       -1     
- Misses      18988    19001      +13     
- Partials     1927     1930       +3     

Impacted Files	Coverage Δ
layer1/executor/task_scheduler.go	1.16% <0.00%> (-0.05%)	⬇️
peering/active.go	83.01% <0.00%> (-0.95%)	⬇️
badgerTrie/smt_merkle_proof.go	64.84% <0.00%> (ø)

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[ghost]

LGTM!