Move commit pointer of submodule Java Models Library.

[NlightNFotis]

This allows us to include a change (diffblue/java-models-library@012cdc2)
that makes it possible to now build under Java version 17, allowing us
to once more release under Homebrew, seeing as now there should be no blockers
to build.

• Each commit message has a non-empty body, explaining why the change was made.
• 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/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

Merging #6350 (860d60d) into develop (bb4c90b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #6350   +/-   ##
========================================
  Coverage    75.90%   75.90%           
========================================
  Files         1515     1515           
  Lines       164005   164005           
========================================
  Hits        124484   124484           
  Misses       39521    39521           

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