loguru: update for BSD fixes

Includes emilk/loguru#245 and commits needed to
allow them to apply cleanly.

Author: mathstuf

ThirdParty/loguru/update.sh

@@ -8,7 +8,7 @@ readonly name="loguru"
 readonly ownership="loguru Upstream <[email protected]>"
 readonly subtree="ThirdParty/$name/vtk$name"
 readonly repo="https://gitlab.kitware.com/third-party/loguru.git"
-readonly tag="for/vtk-20230822-2.1.0"
+readonly tag="for/vtk-20231017-2.1.0"
 readonly paths="
 CMakeLists.vtk.txt
 .gitattributes