Avoid usage of STDERR constant

[dwsupplee]

Closes: #1741

We can prevent errors regarding the lack of the STDERR constant outside of CLI context when creating a resource manually through fopen('php://stderr', 'w').

[codecov]

Codecov Report

Merging #1818 into master will not change coverage.
The diff coverage is 75%.

@@            Coverage Diff            @@
##             master    #1818   +/-   ##
=========================================
  Coverage     91.53%   91.53%           
+ Complexity     4371     4368    -3     
=========================================
  Files           304      304           
  Lines         12914    12914           
=========================================
  Hits          11821    11821           
  Misses         1093     1093

Impacted Files	Coverage Δ	Complexity Δ
Core/src/Batch/BatchTrait.php	88.33% <75%> (ø)	12 <0> (-3)	⬇️

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