Fixed shared_ptr type selection in createSharedInstance

[johnwason]

The return type switch to std::shared_ptr to boost::shared_ptr happened in boost 1.88.0. This adds a few more condition checks to correct the type selection.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.35%. Comparing base (288bf38) to head (4e95cc5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #29   +/-   ##
=======================================
  Coverage   98.35%   98.35%           
=======================================
  Files           2        2           
  Lines         182      182           
=======================================
  Hits          179      179           
  Misses          3        3           

Files with missing lines	Coverage Δ
include/boost_plugin_loader/plugin_loader.hpp	99.05% <100.00%> (ø)

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[johnwason]

@Levi-Armstrong fixed noble build as mentioned in #26