MIR-670 SharedMemoryLoader: send logs to debug channel

[raguridan]

Use Log::debug instead of Log::info to output the shared memory loader logs.

[FussyDuck]

All committers have signed the CLA.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 48.45%. Comparing base (1b2408f) to head (9a94027).
Report is 1 commits behind head on release/1.22.0.

Files	Patch %	Lines
src/mir/caching/legendre/SharedMemoryLoader.cc	0.00%	1 Missing ⚠️
src/mir/caching/matrix/SharedMemoryLoader.cc	0.00%	1 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           release/1.22.0      #20   +/-   ##
===============================================
  Coverage           48.45%   48.45%           
===============================================
  Files                 669      669           
  Lines               28002    28002           
  Branches             2532     2532           
===============================================
  Hits                13568    13568           
  Misses              14434    14434           

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