Installation: drop GCC dependency on FreeBSD

System tomlplusplus is built against libc++ which conflicts with
libstdc++ used by GCC. While tomlplusplus can be bundled it's only
easy to do via Meson (--force-fallback-for).

/usr/local/bin/ld: hyprpm/CMakeFiles/hyprpm.dir/src/core/DataState.cpp.o: in function `DataState::addNewPluginRepo(SPluginRepository const&)':
DataState.cpp:(.text+0x16b4): undefined reference to `toml::v3::table::get_lower_bound(std::basic_string_view<char, std::char_traits<char> >)'
/usr/local/bin/ld: DataState.cpp:(.text+0x1793): undefined reference to `toml::v3::table::insert_with_hint(toml::v3::impl::table_iterator<true>, toml::v3::key&&, std::unique_ptr<toml::v3::node, std::default_delete<toml::v3::node> >&&)'
/usr/local/bin/ld: DataState.cpp:(.text+0x2c59): undefined reference to `toml::v3::impl::print_to_stream(std::ostream&, toml::v3::table const&)'
/usr/local/bin/ld: hyprpm/CMakeFiles/hyprpm.dir/src/core/DataState.cpp.o: in function `DataState::pluginRepoExists(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
DataState.cpp:(.text+0x3739): undefined reference to `toml::v3::ex::parse_file(std::basic_string_view<char, std::char_traits<char> >)'
/usr/local/bin/ld: DataState.cpp:(.text+0x3783): undefined reference to `toml::v3::table::get(std::basic_string_view<char, std::char_traits<char> >)'
/usr/local/bin/ld: DataState.cpp:(.text+0x37ab): undefined reference to `toml::v3::table::get(std::basic_string_view<char, std::char_traits<char> >)'
[...]

pages/Getting Started/Installation.md

@@ -185,12 +185,12 @@ zypper in gcc-c++ git meson cmake "pkgconfig(cairo)" "pkgconfig(egl)" "pkgconfig
 
 (this should also work on RHEL/Fedora if you remove `Mesa-libGLESv3-devel` and `pkgconfig(xcb-errors)`)
 
-_FreeBSD dependencies_:
+_FreeBSD >= 13.3/14.0 dependencies_:
 
 ```plain
-pkg install git pkgconf gmake gcc13 evdev-proto cmake wayland-protocols wayland libglvnd libxkbcommon libinput cairo pango pixman tomlplusplus libxcb
+pkg install git pkgconf gmake evdev-proto cmake wayland-protocols wayland libglvnd libxkbcommon libinput cairo pango pixman tomlplusplus libxcb
 pkg install meson jq `pkg rquery %dn wlroots` hwdata
-export CC=gcc13 CXX=g++13 LDFLAGS="-static-libstdc++ -static-libgcc"
+export CXXFLAGS=-fexperimental-library
 ```
 
 _Ubuntu 23.04 dependencies_: