Migrate from cvc5-1.1.1 to 1.3.1

This is primarily motivated by bringing in the changes from
cvc5/cvc5#11861, which brings in a newer version of
`libpoly` that is compatible with recent versions of Apple `clang++`. (See
SRI-CSL/libpoly#85 for the relevant `libpoly` patch.)
This, in turn, allows `libpoly` to build with `macos-15` CI runners.

Note that recent versions of `cvc5` no longer require patching out the use of
the `ld.gold` linker on Windows, so we can remove the corresponding
`what4-solvers` patch that does this.

Author: RyanGlScott

.github/ci.sh

@@ -119,12 +119,6 @@ build_cvc4() {
 build_cvc5() {
   pushd repos/cvc5
   if $IS_WIN ; then
-    # GitHub Actions comes preinstalled with Chocolatey's mingw package, which
-    # includes the ld.gold linker. This does not play nicely with MSYS2's
-    # mingw-w64-x86_64-gcc, so we must prevent CMake from using ld.gold.
-    # (Ideally, there would be a CMake configuration option to accomplish this,
-    # but I have not found one.)
-    patch -p1 -i $PATCHES/cvc5-no-ld-gold.patch
     # Why do we manually override Python_EXECUTABLE below? GitHub Actions comes
     # with multiple versions of Python pre-installed, and for some bizarre
     # reason, CMake always tries to pick the latest version, even if it is not

README.md

@@ -13,7 +13,7 @@ Currently, `what4-solvers` offers the following solver versions:
 * Bitwuzla - [0.7.0](https://github.com/bitwuzla/bitwuzla/tree/3cf7c35b97c60016883cc19c4d6a9344a989a4d6)
 * Boolector - [3.2.2](https://github.com/Boolector/boolector/tree/e7aba964f69cd52dbe509e46e818a4411b316cd3)
 * CVC4 - [1.8](https://github.com/CVC4/CVC4-archived/tree/5247901077efbc7b9016ba35fded7a6ab459a379)
-* CVC5 - [1.1.1](https://github.com/cvc5/cvc5/tree/ebfdf84d5698eeb83e0fa4e45101fe4a8f4543eb)
+* CVC5 - [1.3.1](https://github.com/cvc5/cvc5/tree/ea1b484fa54bfe56c0f8b3ac90a6e3e2f46441e7)
 * Yices - [2.6.5](https://github.com/SRI-CSL/yices2/tree/8e6297e233299631147f98659224c3118fc6a215)
 * Z3 - [4.8.8](https://github.com/Z3Prover/z3/tree/ad55a1f1c617a7f0c3dd735c0780fc758424c7f1) and
        [4.8.14](https://github.com/Z3Prover/z3/tree/df8f9d7dcb8b9f9b3de1072017b7c2b7f63f0af8)