Fix PHP7.4+ compatibility

[avsdev-cw]

PHP 7.4 modified the method_exists behaviour so that it no longer works as required. Alternative is to use is_callable, however this always returns true when __call is present (which it is). Laravel kindly provides a method for checking if a macro exists, so use that instead.

This fixes the exception in #1143 but more work needs to be done for the UI to access soft-deleted items for hard deleting

[avsdev-cw]

see: See: https://www.php.net/manual/en/function.method-exists.php#124462
and: https://www.php.net/manual/en/function.is-callable.php Notes section

[codecov]

Codecov Report

Merging #1193 (4609904) into master (15d713a) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #1193      +/-   ##
============================================
+ Coverage     70.69%   70.70%   +0.01%     
  Complexity     1983     1983              
============================================
  Files           173      173              
  Lines          6903     6903              
============================================
+ Hits           4880     4881       +1     
+ Misses         2023     2022       -1     

Impacted Files	Coverage Δ
app/sprinkles/core/src/Database/Models/Model.php	73.07% <100.00%> (+3.84%)	⬆️

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