chore(ci): increase bench timeout to 6h

[moul]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.97%. Comparing base (628f965) to head (283b533).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2914   +/-   ##
=======================================
  Coverage   60.96%   60.97%           
=======================================
  Files         564      564           
  Lines       75273    75273           
=======================================
+ Hits        45893    45897    +4     
+ Misses      26009    26008    -1     
+ Partials     3371     3368    -3     

Flag	Coverage Δ
contribs/gnodev	61.46% <ø> (ø)
contribs/gnofaucet	15.31% <ø> (+0.85%)	⬆️
gno.land	67.92% <ø> (ø)
gnovm	65.78% <ø> (ø)
misc/genstd	80.54% <ø> (ø)
misc/logos	19.88% <ø> (ø)
tm2	62.12% <ø> (-0.02%)	⬇️

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[sw360cab]

I don't think it is a matter of timeout, rather of capabilities and performance of the target machine.
Indeed the job did not timed out, but was unable to communicate with target runner at some point.

Let me try to tune the target runner hw and see what happens re running the bench test suite.

[moul]

Related #2915