Remove unused and add missing deprecated.h includes (#3599)

I generated lists of includes and uses via
`rg -l deprecated.h | sort -u` and `rg -l WPI_DEPRECATED | sort -u`
respectively. If a file was in the first list but not the second, the
include was unused. If a file was in the second list but not the first,
the include needed to be added.

ntcore/src/main/native/include/ntcore_c.h

@@ -13,8 +13,6 @@
 #include <stddef.h>
 #endif
 
-#include <wpi/deprecated.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif

wpilibc/src/main/native/include/frc/Encoder.h

@@ -7,6 +7,7 @@
 #include <memory>
 
 #include <hal/Types.h>
+#include <wpi/deprecated.h>
 #include <wpi/sendable/Sendable.h>
 #include <wpi/sendable/SendableHelper.h>
 

wpiutil/src/main/native/include/wpi/StringMap.h

@@ -20,7 +20,6 @@
 #include "wpi/MemAlloc.h"
 #include "wpi/PointerLikeTypeTraits.h"
 #include "wpi/ErrorHandling.h"
-#include "wpi/deprecated.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>

wpiutil/src/main/native/include/wpi/jni_util.h

@@ -19,7 +19,6 @@
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
 #include "wpi/StringExtras.h"
-#include "wpi/deprecated.h"
 #include "wpi/mutex.h"
 #include "wpi/raw_ostream.h"
 #include "wpi/span.h"