Upgrade CVC5 in CI to 1.2.1

[tautschnig]

This prepares for Arm64 runs: CVC5 CI releases CVC5 for Arm64 starting from 1.2.0.

• Each commit message has a non-empty body, explaining why the change was made.
• n/a Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• n/a 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).
• n/a My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• n/a White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.37%. Comparing base (41e9f3d) to head (44a77b3).
Report is 6 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8585      +/-   ##
===========================================
- Coverage    80.38%   80.37%   -0.01%     
===========================================
  Files         1686     1686              
  Lines       206770   206770              
  Branches        85       85              
===========================================
- Hits        166207   166197      -10     
- Misses       40563    40573      +10     

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