Remove deprecated add_axioms_from_long method

[tautschnig]

Removes the deprecated string_constraint_generatort::add_axioms_from_long method and inlines its implementation at the call site.

Fixes: #8021

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• Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.46%. Comparing base (6df204e) to head (127e012).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8918      +/-   ##
===========================================
- Coverage    80.46%   80.46%   -0.01%     
===========================================
  Files         1704     1704              
  Lines       188665   188663       -2     
  Branches        73       73              
===========================================
- Hits        151805   151800       -5     
- Misses       36860    36863       +3     

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[Copilot]

Pull request overview

This PR removes the deprecated string_constraint_generatort::add_axioms_from_long helper and keeps the ID_cprover_string_of_long_func behavior by inlining the former implementation at the dispatch call site.

Changes:

• Removed the add_axioms_from_long declaration from the generator header.
• Deleted the deprecated add_axioms_from_long definition from string_constraint_generator_valueof.cpp.
• Inlined the prior add_axioms_from_long logic inside add_axioms_for_function_application for ID_cprover_string_of_long_func.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/solvers/strings/string_constraint_generator.h	Removes the deprecated method declaration from the class interface.
src/solvers/strings/string_constraint_generator_valueof.cpp	Deletes the deprecated method implementation.
src/solvers/strings/string_constraint_generator_main.cpp	Inlines the removed method’s logic at the ID_cprover_string_of_long_func dispatch site.

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