build: Unbreak build on FreeBSD (#98)

* helpers: add missing header after 9dfb9e125b

src/helpers/MiscFunctions.cpp: In function 'void addHyprlandNotification(const std::string&, float, const std::string&, const std::string&)':
src/helpers/MiscFunctions.cpp:24:9: error: 'fork' was not declared in this scope
   24 |     if (fork() == 0)
      |         ^~~~
src/helpers/MiscFunctions.cpp:25:9: error: 'execl' was not declared in this scope
   25 |         execl("/bin/sh", "/bin/sh", "-c", CMD.c_str(), nullptr);
      |         ^~~~~

* build: add missing dependency for libc++ after 2f48e65503

ld.lld: error: undefined symbol: pthread_create
>>> referenced by PortalManager.cpp
>>>               src/xdg-desktop-portal-hyprland.p/core_PortalManager.cpp.o:(CPortalManager::startEventLoop())
>>> referenced by PortalManager.cpp
>>>               src/xdg-desktop-portal-hyprland.p/core_PortalManager.cpp.o:(CPortalManager::startEventLoop())

CMakeLists.txt

@@ -31,12 +31,14 @@ message(STATUS "Checking deps...")
 add_subdirectory(subprojects/sdbus-cpp)
 add_subdirectory(hyprland-share-picker)
 
+find_package(Threads REQUIRED)
+
 find_package(PkgConfig REQUIRED)
 pkg_check_modules(deps REQUIRED IMPORTED_TARGET wayland-client wayland-protocols libpipewire-0.3 libspa-0.2 libdrm gbm)
 
 file(GLOB_RECURSE SRCFILES CONFIGURE_DEPENDS "src/*.cpp")
 add_executable(xdg-desktop-portal-hyprland ${SRCFILES})
-target_link_libraries(xdg-desktop-portal-hyprland PRIVATE rt sdbus-c++ PkgConfig::deps)
+target_link_libraries(xdg-desktop-portal-hyprland PRIVATE rt sdbus-c++ Threads::Threads PkgConfig::deps)
 
 # protocols
 find_program(WaylandScanner NAMES wayland-scanner)

src/helpers/MiscFunctions.cpp

@@ -1,5 +1,6 @@
 #include "MiscFunctions.hpp"
 #include <memory>
+#include <unistd.h>
 #include "../helpers/Log.hpp"
 
 std::string execAndGet(const char* cmd) {

src/meson.build

@@ -8,6 +8,7 @@ executable('xdg-desktop-portal-hyprland',
     dependency('libdrm'),
     dependency('libpipewire-0.3'),
     dependency('sdbus-c++'),
+    dependency('threads'),
     dependency('wayland-client'),
   ],
   include_directories: inc,