chore: Remove unused Psalm issue handler suppression

Remove UndefinedInterfaceMethod suppression for AppConfiguration.php
as it's no longer needed. This fixes SARIF validation errors in the
GitHub Security workflow where Psalm generated invalid location data
(startLine: 0) for unused suppressions.

Author: nplhse

psalm.xml

@@ -56,11 +56,6 @@
                 <directory name="src/Import/Infrastructure/Adapter/" />
             </errorLevel>
         </PossiblyUnusedProperty>
-        <UndefinedInterfaceMethod>
-            <errorLevel type="suppress">
-                <file name="src/Shared/Infrastructure/DependencyInjection/AppConfiguration.php" />
-            </errorLevel>
-        </UndefinedInterfaceMethod>
         <UnusedClass>
             <errorLevel type="suppress">
                 <directory name="src/*/Application/MessageHandler/" />