Kernel: Remove Process::all_processes()

This was only used in ProcFS, which can use the `processes()` list just
as well, so let's remove it.

Kernel/GlobalProcessExposed.cpp

@@ -533,10 +533,11 @@ private:
         {
             {
                 auto array = json.add_array("processes");
-                auto processes = Process::all_processes();
                 build_process(array, *Scheduler::colonel());
-                for (auto& process : processes)
-                    build_process(array, process);
+                processes().with([&](auto& processes) {
+                    for (auto& process : processes)
+                        build_process(array, process);
+                });
             }
 
             auto total_time_scheduled = Scheduler::get_total_time_scheduled();

Kernel/Process.cpp

@@ -79,17 +79,6 @@ UNMAP_AFTER_INIT void Process::initialize()
     create_signal_trampoline();
 }
 
-NonnullRefPtrVector<Process> Process::all_processes()
-{
-    NonnullRefPtrVector<Process> output;
-    processes().with([&](const auto& list) {
-        output.ensure_capacity(list.size_slow());
-        for (const auto& process : list)
-            output.append(NonnullRefPtr<Process>(process));
-    });
-    return output;
-}
-
 bool Process::in_group(GroupID gid) const
 {
     return this->gid() == gid || extra_gids().contains_slow(gid);

Kernel/Process.h

@@ -186,8 +186,6 @@ public:
     bool unref() const;
     ~Process();
 
-    static NonnullRefPtrVector<Process> all_processes();
-
     RefPtr<Thread> create_kernel_thread(void (*entry)(void*), void* entry_data, u32 priority, NonnullOwnPtr<KString> name, u32 affinity = THREAD_AFFINITY_DEFAULT, bool joinable = true);
 
     bool is_profiling() const { return m_profiling; }