Kernel: Remove ThreadTracer.h include from Process.h / Thread.h

This isn't needed for Process / Thread as they only reference it
by pointer and it's already part of Kernel/Forward.h. So just include
it where the implementation needs to call it.

Kernel/Arch/x86/common/Interrupts.cpp

@@ -17,6 +17,7 @@
 #include <Kernel/Random.h>
 #include <Kernel/Sections.h>
 #include <Kernel/Thread.h>
+#include <Kernel/ThreadTracer.h>
 
 #include <LibC/mallocdefs.h>
 

Kernel/Process.cpp

@@ -31,6 +31,7 @@
 #include <Kernel/StdLib.h>
 #include <Kernel/TTY/TTY.h>
 #include <Kernel/Thread.h>
+#include <Kernel/ThreadTracer.h>
 #include <Kernel/VM/AnonymousVMObject.h>
 #include <Kernel/VM/PageDirectory.h>
 #include <Kernel/VM/SharedInodeVMObject.h>

Kernel/Process.h

@@ -25,7 +25,6 @@
 #include <Kernel/ProcessGroup.h>
 #include <Kernel/StdLib.h>
 #include <Kernel/Thread.h>
-#include <Kernel/ThreadTracer.h>
 #include <Kernel/UnixTypes.h>
 #include <Kernel/UnveilNode.h>
 #include <Kernel/VM/Space.h>

Kernel/Syscalls/ptrace.cpp

@@ -7,6 +7,7 @@
 
 #include <AK/ScopeGuard.h>
 #include <Kernel/Process.h>
+#include <Kernel/ThreadTracer.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <Kernel/VM/PrivateInodeVMObject.h>
 #include <Kernel/VM/ProcessPagingScope.h>

Kernel/Thread.h

@@ -28,7 +28,6 @@
 #include <Kernel/KResult.h>
 #include <Kernel/LockMode.h>
 #include <Kernel/Scheduler.h>
-#include <Kernel/ThreadTracer.h>
 #include <Kernel/TimerQueue.h>
 #include <Kernel/UnixTypes.h>
 #include <Kernel/VM/Range.h>