Install cvc5 on Windows pull request jobs

[thomasspriggs]

This PR installs cvc5 on Windows pull request jobs, so that we can test with cvc5 across all platforms.

• 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 #6778 (6127938) into develop (f1dd8db) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #6778   +/-   ##
========================================
  Coverage    76.90%   76.90%           
========================================
  Files         1590     1590           
  Lines       183970   183970           
========================================
  Hits        141485   141485           
  Misses       42485    42485           

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