Remove initial value for output of Keithley 2450

[aaronsharpe]

Setting an initial value for the keithley output is quite dangerous, especially when recovering from a kernel crash. Initializing the instrument should leave the output state unchanged<!--

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[aaronsharpe]

Sorry about the mix up on the last pull request. Let me know if this change warrants newsfragment

[codecov]

Codecov Report

Merging #5572 (9a6b09d) into main (eb439f8) will increase coverage by 0.06%.
Report is 82 commits behind head on main.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5572      +/-   ##
==========================================
+ Coverage   66.32%   66.38%   +0.06%     
==========================================
  Files         354      354              
  Lines       30958    30960       +2     
==========================================
+ Hits        20532    20554      +22     
+ Misses      10426    10406      -20     

[jenshnielsen]

@aaronsharpe thanks, I think it would be good with a neswfragment since this changes the behaviour even if it’s for the better

[aaronsharpe]

Added. Thanks for the feedback