Update fmt and spdlog (#174)

* Update dependency spdlog to v1.16.0

* Update dependency fmt to v12

* Update conan lock

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: nikobockerman

solvers/cpp/conan.lock

@@ -1,9 +1,9 @@
 {
     "version": "0.5",
     "requires": [
-        "spdlog/1.15.3#3ca0e9e6b83af4d0151e26541d140c86%1748617970.519",
+        "spdlog/1.16.0#942c2c39562ae25ba575d9c8e2bdf3b6%1760375663.769",
         "gtest/1.17.0#5224b3b3ff3b4ce1133cbdd27d53ee7d%1755784855.585",
-        "fmt/11.2.0#579bb2cdf4a7607621beea4eb4651e0f%1746298708.362"
+        "fmt/12.0.0#dc7de7f3968e5d6b377f27b7d0f33916%1758262922.745"
     ],
     "build_requires": [
         "cmake/4.1.0#c45377ac8029e0a1738a0c40269991c3%1754591635.125"

solvers/cpp/conanfile.txt

@@ -1,6 +1,6 @@
 [requires]
-fmt/11.2.0
-spdlog/1.15.3
+fmt/12.0.0
+spdlog/1.16.0
 gtest/1.17.0
 
 [generators]